aboutsummaryrefslogtreecommitdiffstats
path: root/sound/core/pcm_lib.c
blob: fd300c3adddec999e9584f3a0e0bc8884198b2b3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Digital Audio (PCM) abstract layer
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *                   Abramo Bagnara <abramo@alsa-project.org>
 */

#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/time.h>
#include <linux/math64.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/tlv.h>
#include <sound/info.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/timer.h>

#include "pcm_local.h"

#ifdef CONFIG_SND_PCM_XRUN_DEBUG
#define CREATE_TRACE_POINTS
#include "pcm_trace.h"
#else
#define trace_hwptr(substream, pos, in_interrupt)
#define trace_xrun(substream)
#define trace_hw_ptr_error(substream, reason)
#define trace_applptr(substream, prev, curr)
#endif

static int fill_silence_frames(struct snd_pcm_substream *substream,
			       snd_pcm_uframes_t off, snd_pcm_uframes_t frames);

/*
 * fill ring buffer with silence
 * runtime->silence_start: starting pointer to silence area
 * runtime->silence_filled: size filled with silence
 * runtime->silence_threshold: threshold from application
 * runtime->silence_size: maximal size from application
 *
 * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
 */
void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_uframes_t frames, ofs, transfer;
	int err;

	if (runtime->silence_size < runtime->boundary) {
		snd_pcm_sframes_t noise_dist, n;
		snd_pcm_uframes_t appl_ptr = READ_ONCE(runtime->control->appl_ptr);
		if (runtime->silence_start != appl_ptr) {
			n = appl_ptr - runtime->silence_start;
			if (n < 0)
				n += runtime->boundary;
			if ((snd_pcm_uframes_t)n < runtime->silence_filled)
				runtime->silence_filled -= n;
			else
				runtime->silence_filled = 0;
			runtime->silence_start = appl_ptr;
		}
		if (runtime->silence_filled >= runtime->buffer_size)
			return;
		noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
		if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
			return;
		frames = runtime->silence_threshold - noise_dist;
		if (frames > runtime->silence_size)
			frames = runtime->silence_size;
	} else {
		if (new_hw_ptr == ULONG_MAX) {	/* initialization */
			snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
			if (avail > runtime->buffer_size)
				avail = runtime->buffer_size;
			runtime->silence_filled = avail > 0 ? avail : 0;
			runtime->silence_start = (runtime->status->hw_ptr +
						  runtime->silence_filled) %
						 runtime->boundary;
		} else {
			ofs = runtime->status->hw_ptr;
			frames = new_hw_ptr - ofs;
			if ((snd_pcm_sframes_t)frames < 0)
				frames += runtime->boundary;
			runtime->silence_filled -= frames;
			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
				runtime->silence_filled = 0;
				runtime->silence_start = new_hw_ptr;
			} else {
				runtime->silence_start = ofs;
			}
		}
		frames = runtime->buffer_size - runtime->silence_filled;
	}
	if (snd_BUG_ON(frames > runtime->buffer_size))
		return;
	if (frames == 0)
		return;
	ofs = runtime->silence_start % runtime->buffer_size;
	while (frames > 0) {
		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
		err = fill_silence_frames(substream, ofs, transfer);
		snd_BUG_ON(err < 0);
		runtime->silence_filled += transfer;
		frames -= transfer;
		ofs = 0;
	}
}

#ifdef CONFIG_SND_DEBUG
void snd_pcm_debug_name(struct snd_pcm_substream *substream,
			   char *name, size_t len)
{
	snprintf(name, len, "pcmC%dD%d%c:%d",
		 substream->pcm->card->number,
		 substream->pcm->device,
		 substream->stream ? 'c' : 'p',
		 substream->number);
}
EXPORT_SYMBOL(snd_pcm_debug_name);
#endif

#define XRUN_DEBUG_BASIC	(1<<0)
#define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
#define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */

#ifdef CONFIG_SND_PCM_XRUN_DEBUG

#define xrun_debug(substream, mask) \
			((substream)->pstr->xrun_debug & (mask))
#else
#define xrun_debug(substream, mask)	0
#endif

#define dump_stack_on_xrun(substream) do {			\
		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
			dump_stack();				\
	} while (0)

/* call with stream lock held */
void __snd_pcm_xrun(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;

	trace_xrun(substream);
	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
		char name[16];
		snd_pcm_debug_name(substream, name, sizeof(name));
		pcm_warn(substream->pcm, "XRUN: %s\n", name);
		dump_stack_on_xrun(substream);
	}
}

#ifdef CONFIG_SND_PCM_XRUN_DEBUG
#define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)	\
	do {								\
		trace_hw_ptr_error(substream, reason);	\
		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
			pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
					   (in_interrupt) ? 'Q' : 'P', ##args);	\
			dump_stack_on_xrun(substream);			\
		}							\
	} while (0)

#else /* ! CONFIG_SND_PCM_XRUN_DEBUG */

#define hw_ptr_error(substream, fmt, args...) do { } while (0)

#endif

int snd_pcm_update_state(struct snd_pcm_substream *substream,
			 struct snd_pcm_runtime *runtime)
{
	snd_pcm_uframes_t avail;

	avail = snd_pcm_avail(substream);
	if (avail > runtime->avail_max)
		runtime->avail_max = avail;
	if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
		if (avail >= runtime->buffer_size) {
			snd_pcm_drain_done(substream);
			return -EPIPE;
		}
	} else {
		if (avail >= runtime->stop_threshold) {
			__snd_pcm_xrun(substream);
			return -EPIPE;
		}
	}
	if (runtime->twake) {
		if (avail >= runtime->twake)
			wake_up(&runtime->tsleep);
	} else if (avail >= runtime->control->avail_min)
		wake_up(&runtime->sleep);
	return 0;
}

static void update_audio_tstamp(struct snd_pcm_substream *substream,
				struct timespec *curr_tstamp,
				struct timespec *audio_tstamp)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	u64 audio_frames, audio_nsecs;
	struct timespec driver_tstamp;

	if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
		return;

	if (!(substream->ops->get_time_info) ||
		(runtime->audio_tstamp_report.actual_type ==
			SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {

		/*
		 * provide audio timestamp derived from pointer position
		 * add delay only if requested
		 */

		audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;

		if (runtime->audio_tstamp_config.report_delay) {
			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
				audio_frames -=  runtime->delay;
			else
				audio_frames +=  runtime->delay;
		}
		audio_nsecs = div_u64(audio_frames * 1000000000LL,
				runtime->rate);
		*audio_tstamp = ns_to_timespec(audio_nsecs);
	}
	if (!timespec_equal(&runtime->status->audio_tstamp, audio_tstamp)) {
		runtime->status->audio_tstamp = *audio_tstamp;
		runtime->status->tstamp = *curr_tstamp;
	}

	/*
	 * re-take a driver timestamp to let apps detect if the reference tstamp
	 * read by low-level hardware was provided with a delay
	 */
	snd_pcm_gettime(substream->runtime, (struct timespec *)&driver_tstamp);
	runtime->driver_tstamp = driver_tstamp;
}

static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
				  unsigned int in_interrupt)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_uframes_t pos;
	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
	snd_pcm_sframes_t hdelta, delta;
	unsigned long jdelta;
	unsigned long curr_jiffies;
	struct timespec curr_tstamp;
	struct timespec audio_tstamp;
	int crossed_boundary = 0;

	old_hw_ptr = runtime->status->hw_ptr;

	/*
	 * group pointer, time and jiffies reads to allow for more
	 * accurate correlations/corrections.
	 * The values are stored at the end of this routine after
	 * corrections for hw_ptr position
	 */
	pos = substream->ops->pointer(substream);
	curr_jiffies = jiffies;
	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
		if ((substream->ops->get_time_info) &&
			(runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
			substream->ops->get_time_info(substream, &curr_tstamp,
						&audio_tstamp,
						&runtime->audio_tstamp_config,
						&runtime->audio_tstamp_report);

			/* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
			if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
				snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
		} else
			snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
	}

	if (pos == SNDRV_PCM_POS_XRUN) {
		__snd_pcm_xrun(substream);
		return -EPIPE;
	}
	if (pos >= runtime->buffer_size) {
		if (printk_ratelimit()) {
			char name[16];
			snd_pcm_debug_name(substream, name, sizeof(name));
			pcm_err(substream->pcm,
				"invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
				name, pos, runtime->buffer_size,
				runtime->period_size);
		}
		pos = 0;
	}
	pos -= pos % runtime->min_align;
	trace_hwptr(substream, pos, in_interrupt);
	hw_base = runtime->hw_ptr_base;
	new_hw_ptr = hw_base + pos;
	if (in_interrupt) {
		/* we know that one period was processed */
		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
		delta = runtime->hw_ptr_interrupt + runtime->period_size;
		if (delta > new_hw_ptr) {
			/* check for double acknowledged interrupts */
			hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
			if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
				hw_base += runtime->buffer_size;
				if (hw_base >= runtime->boundary) {
					hw_base = 0;
					crossed_boundary++;
				}
				new_hw_ptr = hw_base + pos;
				goto __delta;
			}
		}
	}
	/* new_hw_ptr might be lower than old_hw_ptr in case when */
	/* pointer crosses the end of the ring buffer */
	if (new_hw_ptr < old_hw_ptr) {
		hw_base += runtime->buffer_size;
		if (hw_base >= runtime->boundary) {
			hw_base = 0;
			crossed_boundary++;
		}
		new_hw_ptr = hw_base + pos;
	}
      __delta:
	delta = new_hw_ptr - old_hw_ptr;
	if (delta < 0)
		delta += runtime->boundary;

	if (runtime->no_period_wakeup) {
		snd_pcm_sframes_t xrun_threshold;
		/*
		 * Without regular period interrupts, we have to check
		 * the elapsed time to detect xruns.
		 */
		jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
			goto no_delta_check;
		hdelta = jdelta - delta * HZ / runtime->rate;
		xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
		while (hdelta > xrun_threshold) {
			delta += runtime->buffer_size;
			hw_base += runtime->buffer_size;
			if (hw_base >= runtime->boundary) {
				hw_base = 0;
				crossed_boundary++;
			}
			new_hw_ptr = hw_base + pos;
			hdelta -= runtime->hw_ptr_buffer_jiffies;
		}
		goto no_delta_check;
	}

	/* something must be really wrong */
	if (delta >= runtime->buffer_size + runtime->period_size) {
		hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
			     "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
			     substream->stream, (long)pos,
			     (long)new_hw_ptr, (long)old_hw_ptr);
		return 0;
	}

	/* Do jiffies check only in xrun_debug mode */
	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
		goto no_jiffies_check;

	/* Skip the jiffies check for hardwares with BATCH flag.
	 * Such hardware usually just increases the position at each IRQ,
	 * thus it can't give any strange position.
	 */
	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
		goto no_jiffies_check;
	hdelta = delta;
	if (hdelta < runtime->delay)
		goto no_jiffies_check;
	hdelta -= runtime->delay;
	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
		delta = jdelta /
			(((runtime->period_size * HZ) / runtime->rate)
								+ HZ/100);
		/* move new_hw_ptr according jiffies not pos variable */
		new_hw_ptr = old_hw_ptr;
		hw_base = delta;
		/* use loop to avoid checks for delta overflows */
		/* the delta value is small or zero in most cases */
		while (delta > 0) {
			new_hw_ptr += runtime->period_size;
			if (new_hw_ptr >= runtime->boundary) {
				new_hw_ptr -= runtime->boundary;
				crossed_boundary--;
			}
			delta--;
		}
		/* align hw_base to buffer_size */
		hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
			     "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
			     (long)pos, (long)hdelta,
			     (long)runtime->period_size, jdelta,
			     ((hdelta * HZ) / runtime->rate), hw_base,
			     (unsigned long)old_hw_ptr,
			     (unsigned long)new_hw_ptr);
		/* reset values to proper state */
		delta = 0;
		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
	}
 no_jiffies_check:
	if (delta > runtime->period_size + runtime->period_size / 2) {
		hw_ptr_error(substream, in_interrupt,
			     "Lost interrupts?",
			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
			     substream->stream, (long)delta,
			     (long)new_hw_ptr,
			     (long)old_hw_ptr);
	}

 no_delta_check:
	if (runtime->status->hw_ptr == new_hw_ptr) {
		runtime->hw_ptr_jiffies = curr_jiffies;
		update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
		return 0;
	}

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
	    runtime->silence_size > 0)
		snd_pcm_playback_silence(substream, new_hw_ptr);

	if (in_interrupt) {
		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
		if (delta < 0)
			delta += runtime->boundary;
		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
		runtime->hw_ptr_interrupt += delta;
		if (runtime->hw_ptr_interrupt >= runtime->boundary)
			runtime->hw_ptr_interrupt -= runtime->boundary;
	}
	runtime->hw_ptr_base = hw_base;
	runtime->status->hw_ptr = new_hw_ptr;
	runtime->hw_ptr_jiffies = curr_jiffies;
	if (crossed_boundary) {
		snd_BUG_ON(crossed_boundary != 1);
		runtime->hw_ptr_wrap += runtime->boundary;
	}

	update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);

	return snd_pcm_update_state(substream, runtime);
}

/* CAUTION: call it with irq disabled */
int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
{
	return snd_pcm_update_hw_ptr0(substream, 0);
}

/**
 * snd_pcm_set_ops - set the PCM operators
 * @pcm: the pcm instance
 * @direction: stream direction, SNDRV_PCM_STREAM_XXX
 * @ops: the operator table
 *
 * Sets the given PCM operators to the pcm instance.
 */
void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
		     const struct snd_pcm_ops *ops)
{
	struct snd_pcm_str *stream = &pcm->streams[direction];
	struct snd_pcm_substream *substream;
	
	for (substream = stream->substream; substream != NULL; substream = substream->next)
		substream->ops = ops;
}
EXPORT_SYMBOL(snd_pcm_set_ops);

/**
 * snd_pcm_sync - set the PCM sync id
 * @substream: the pcm substream
 *
 * Sets the PCM sync identifier for the card.
 */
void snd_pcm_set_sync(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	
	runtime->sync.id32[0] = substream->pcm->card->number;
	runtime->sync.id32[1] = -1;
	runtime->sync.id32[2] = -1;
	runtime->sync.id32[3] = -1;
}
EXPORT_SYMBOL(snd_pcm_set_sync);

/*
 *  Standard ioctl routine
 */

static inline unsigned int div32(unsigned int a, unsigned int b, 
				 unsigned int *r)
{
	if (b == 0) {
		*r = 0;
		return UINT_MAX;
	}
	*r = a % b;
	return a / b;
}

static inline unsigned int div_down(unsigned int a, unsigned int b)
{
	if (b == 0)
		return UINT_MAX;
	return a / b;
}

static inline unsigned int div_up(unsigned int a, unsigned int b)
{
	unsigned int r;
	unsigned int q;
	if (b == 0)
		return UINT_MAX;
	q = div32(a, b, &r);
	if (r)
		++q;
	return q;
}

static inline unsigned int mul(unsigned int a, unsigned int b)
{
	if (a == 0)
		return 0;
	if (div_down(UINT_MAX, a) < b)
		return UINT_MAX;
	return a * b;
}

static inline unsigned int muldiv32(unsigned int a, unsigned int b,
				    unsigned int c, unsigned int *r)
{
	u_int64_t n = (u_int64_t) a * b;
	if (c == 0) {
		*r = 0;
		return UINT_MAX;
	}
	n = div_u64_rem(n, c, r);
	if (n >= UINT_MAX) {
		*r = 0;
		return UINT_MAX;
	}
	return n;
}

/**
 * snd_interval_refine - refine the interval value of configurator
 * @i: the interval value to refine
 * @v: the interval value to refer to
 *
 * Refines the interval value with the reference value.
 * The interval is changed to the range satisfying both intervals.
 * The interval status (min, max, integer, etc.) are evaluated.
 *
 * Return: Positive if the value is changed, zero if it's not changed, or a
 * negative error code.
 */
int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
{
	int changed = 0;
	if (snd_BUG_ON(snd_interval_empty(i)))
		return -EINVAL;
	if (i->min < v->min) {
		i->min = v->min;
		i->openmin = v->openmin;
		changed = 1;
	} else if (i->min == v->min && !i->openmin && v->openmin) {
		i->openmin = 1;
		changed = 1;
	}
	if (i->max > v->max) {
		i->max = v->max;
		i->openmax = v->openmax;
		changed = 1;
	} else if (i->max == v->max && !i->openmax && v->openmax) {
		i->openmax = 1;
		changed = 1;
	}
	if (!i->integer && v->integer) {
		i->integer = 1;
		changed = 1;
	}
	if (i->integer) {
		if (i->openmin) {
			i->min++;
			i->openmin = 0;
		}
		if (i->openmax) {
			i->max--;
			i->openmax = 0;
		}
	} else if (!i->openmin && !i->openmax && i->min == i->max)
		i->integer = 1;
	if (snd_interval_checkempty(i)) {
		snd_interval_none(i);
		return -EINVAL;
	}
	return changed;
}
EXPORT_SYMBOL(snd_interval_refine);

static int snd_interval_refine_first(struct snd_interval *i)
{
	const unsigned int last_max = i->max;

	if (snd_BUG_ON(snd_interval_empty(i)))
		return -EINVAL;
	if (snd_interval_single(i))
		return 0;
	i->max = i->min;
	if (i->openmin)
		i->max++;
	/* only exclude max value if also excluded before refine */
	i->openmax = (i->openmax && i->max >= last_max);
	return 1;
}

static int snd_interval_refine_last(struct snd_interval *i)
{
	const unsigned int last_min = i->min;

	if (snd_BUG_ON(snd_interval_empty(i)))
		return -EINVAL;
	if (snd_interval_single(i))
		return 0;
	i->min = i->max;
	if (i->openmax)
		i->min--;
	/* only exclude min value if also excluded before refine */
	i->openmin = (i->openmin && i->min <= last_min);
	return 1;
}

void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
{
	if (a->empty || b->empty) {
		snd_interval_none(c);
		return;
	}
	c->empty = 0;
	c->min = mul(a->min, b->min);
	c->openmin = (a->openmin || b->openmin);
	c->max = mul(a->max,  b->max);
	c->openmax = (a->openmax || b->openmax);
	c->integer = (a->integer && b->integer);
}

/**
 * snd_interval_div - refine the interval value with division
 * @a: dividend
 * @b: divisor
 * @c: quotient
 *
 * c = a / b
 *
 * Returns non-zero if the value is changed, zero if not changed.
 */
void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
{
	unsigned int r;
	if (a->empty || b->empty) {
		snd_interval_none(c);
		return;
	}
	c->empty = 0;
	c->min = div32(a->min, b->max, &r);
	c->openmin = (r || a->openmin || b->openmax);
	if (b->min > 0) {
		c->max = div32(a->max, b->min, &r);
		if (r) {
			c->max++;
			c->openmax = 1;
		} else
			c->openmax = (a->openmax || b->openmin);
	} else {
		c->max = UINT_MAX;
		c->openmax = 0;
	}
	c->integer = 0;
}

/**
 * snd_interval_muldivk - refine the interval value
 * @a: dividend 1
 * @b: dividend 2
 * @k: divisor (as integer)
 * @c: result
  *
 * c = a * b / k
 *
 * Returns non-zero if the value is changed, zero if not changed.
 */
void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
		      unsigned int k, struct snd_interval *c)
{
	unsigned int r;
	if (a->empty || b->empty) {
		snd_interval_none(c);
		return;
	}
	c->empty = 0;
	c->min = muldiv32(a->min, b->min, k, &r);
	c->openmin = (r || a->openmin || b->openmin);
	c->max = muldiv32(a->max, b->max, k, &r);
	if (r) {
		c->max++;
		c->openmax = 1;
	} else
		c->openmax = (a->openmax || b->openmax);
	c->integer = 0;
}

/**
 * snd_interval_mulkdiv - refine the interval value
 * @a: dividend 1
 * @k: dividend 2 (as integer)
 * @b: divisor
 * @c: result
 *
 * c = a * k / b
 *
 * Returns non-zero if the value is changed, zero if not changed.
 */
void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
		      const struct snd_interval *b, struct snd_interval *c)
{
	unsigned int r;
	if (a->empty || b->empty) {
		snd_interval_none(c);
		return;
	}
	c->empty = 0;
	c->min = muldiv32(a->min, k, b->max, &r);
	c->openmin = (r || a->openmin || b->openmax);
	if (b->min > 0) {
		c->max = muldiv32(a->max, k, b->min, &r);
		if (r) {
			c->max++;
			c->openmax = 1;
		} else
			c->openmax = (a->openmax || b->openmin);
	} else {
		c->max = UINT_MAX;
		c->openmax = 0;
	}
	c->integer = 0;
}

/* ---- */


/**
 * snd_interval_ratnum - refine the interval value
 * @i: interval to refine
 * @rats_count: number of ratnum_t 
 * @rats: ratnum_t array
 * @nump: pointer to store the resultant numerator
 * @denp: pointer to store the resultant denominator
 *
 * Return: Positive if the value is changed, zero if it's not changed, or a
 * negative error code.
 */
int snd_interval_ratnum(struct snd_interval *i,
			unsigned int rats_count, const struct snd_ratnum *rats,
			unsigned int *nump, unsigned int *denp)
{
	unsigned int best_num, best_den;
	int best_diff;
	unsigned int k;
	struct snd_interval t;
	int err;
	unsigned int result_num, result_den;
	int result_diff;

	best_num = best_den = best_diff = 0;
	for (k = 0; k < rats_count; ++k) {
		unsigned int num = rats[k].num;
		unsigned int den;
		unsigned int q = i->min;
		int diff;
		if (q == 0)
			q = 1;
		den = div_up(num, q);
		if (den < rats[k].den_min)
			continue;
		if (den > rats[k].den_max)
			den = rats[k].den_max;
		else {
			unsigned int r;
			r = (den - rats[k].den_min) % rats[k].den_step;
			if (r != 0)
				den -= r;
		}
		diff = num - q * den;
		if (diff < 0)
			diff = -diff;
		if (best_num == 0 ||
		    diff * best_den < best_diff * den) {
			best_diff = diff;
			best_den = den;
			best_num = num;
		}
	}
	if (best_den == 0) {
		i->empty = 1;
		return -EINVAL;
	}
	t.min = div_down(best_num, best_den);
	t.openmin = !!(best_num % best_den);
	
	result_num = best_num;
	result_diff = best_diff;
	result_den = best_den;
	best_num = best_den = best_diff = 0;
	for (k = 0; k < rats_count; ++k) {
		unsigned int num = rats[k].num;
		unsigned int den;
		unsigned int q = i->max;
		int diff;
		if (q == 0) {
			i->empty = 1;
			return -EINVAL;
		}
		den = div_down(num, q);
		if (den > rats[k].den_max)
			continue;
		if (den < rats[k].den_min)
			den = rats[k].den_min;
		else {
			unsigned int r;
			r = (den - rats[k].den_min) % rats[k].den_step;
			if (r != 0)
				den += rats[k].den_step - r;
		}
		diff = q * den - num;
		if (diff < 0)
			diff = -diff;
		if (best_num == 0 ||
		    diff * best_den < best_diff * den) {
			best_diff = diff;
			best_den = den;
			best_num = num;
		}
	}
	if (best_den == 0) {
		i->empty = 1;
		return -EINVAL;
	}
	t.max = div_up(best_num, best_den);
	t.openmax = !!(best_num % best_den);
	t.integer = 0;
	err = snd_interval_refine(i, &t);
	if (err < 0)
		return err;

	if (snd_interval_single(i)) {
		if (best_diff * result_den < result_diff * best_den) {
			result_num = best_num;
			result_den = best_den;
		}
		if (nump)
			*nump = result_num;
		if (denp)
			*denp = result_den;
	}
	return err;
}
EXPORT_SYMBOL(snd_interval_ratnum);

/**
 * snd_interval_ratden - refine the interval value
 * @i: interval to refine
 * @rats_count: number of struct ratden
 * @rats: struct ratden array
 * @nump: pointer to store the resultant numerator
 * @denp: pointer to store the resultant denominator
 *
 * Return: Positive if the value is changed, zero if it's not changed, or a
 * negative error code.
 */
static int snd_interval_ratden(struct snd_interval *i,
			       unsigned int rats_count,
			       const struct snd_ratden *rats,
			       unsigned int *nump, unsigned int *denp)
{
	unsigned int best_num, best_diff, best_den;
	unsigned int k;
	struct snd_interval t;
	int err;

	best_num = best_den = best_diff = 0;
	for (k = 0; k < rats_count; ++k) {
		unsigned int num;
		unsigned int den = rats[k].den;
		unsigned int q = i->min;
		int diff;
		num = mul(q, den);
		if (num > rats[k].num_max)
			continue;
		if (num < rats[k].num_min)
			num = rats[k].num_max;
		else {
			unsigned int r;
			r = (num - rats[k].num_min) % rats[k].num_step;
			if (r != 0)
				num += rats[k].num_step - r;
		}
		diff = num - q * den;
		if (best_num == 0 ||
		    diff * best_den < best_diff * den) {
			best_diff = diff;
			best_den = den;
			best_num = num;
		}
	}
	if (best_den == 0) {
		i->empty = 1;
		return -EINVAL;
	}
	t.min = div_down(best_num, best_den);
	t.openmin = !!(best_num % best_den);
	
	best_num = best_den = best_diff = 0;
	for (k = 0; k < rats_count; ++k) {
		unsigned int num;
		unsigned int den = rats[k].den;
		unsigned int q = i->max;
		int diff;
		num = mul(q, den);
		if (num < rats[k].num_min)
			continue;
		if (num > rats[k].num_max)
			num = rats[k].num_max;
		else {
			unsigned int r;
			r = (num - rats[k].num_min) % rats[k].num_step;
			if (r != 0)
				num -= r;
		}
		diff = q * den - num;
		if (best_num == 0 ||
		    diff * best_den < best_diff * den) {
			best_diff = diff;
			best_den = den;
			best_num = num;
		}
	}
	if (best_den == 0) {
		i->empty = 1;
		return -EINVAL;
	}
	t.max = div_up(best_num, best_den);
	t.openmax = !!(best_num % best_den);
	t.integer = 0;
	err = snd_interval_refine(i, &t);
	if (err < 0)
		return err;

	if (snd_interval_single(i)) {
		if (nump)
			*nump = best_num;
		if (denp)
			*denp = best_den;
	}
	return err;
}

/**
 * snd_interval_list - refine the interval value from the list
 * @i: the interval value to refine
 * @count: the number of elements in the list
 * @list: the value list
 * @mask: the bit-mask to evaluate
 *
 * Refines the interval value from the list.
 * When mask is non-zero, only the elements corresponding to bit 1 are
 * evaluated.
 *
 * Return: Positive if the value is changed, zero if it's not changed, or a
 * negative error code.
 */
int snd_interval_list(struct snd_interval *i, unsigned int count,
		      const unsigned int *list, unsigned int mask)
{
        unsigned int k;
	struct snd_interval list_range;

	if (!count) {
		i->empty = 1;
		return -EINVAL;
	}
	snd_interval_any(&list_range);
	list_range.min = UINT_MAX;
	list_range.max = 0;
        for (k = 0; k < count; k++) {
		if (mask && !(mask & (1 << k)))
			continue;
		if (!snd_interval_test(i, list[k]))
			continue;
		list_range.min = min(list_range.min, list[k]);
		list_range.max = max(list_range.max, list[k]);
        }
	return snd_interval_refine(i, &list_range);
}
EXPORT_SYMBOL(snd_interval_list);

/**
 * snd_interval_ranges - refine the interval value from the list of ranges
 * @i: the interval value to refine
 * @count: the number of elements in the list of ranges
 * @ranges: the ranges list
 * @mask: the bit-mask to evaluate
 *
 * Refines the interval value from the list of ranges.
 * When mask is non-zero, only the elements corresponding to bit 1 are
 * evaluated.
 *
 * Return: Positive if the value is changed, zero if it's not changed, or a
 * negative error code.
 */
int snd_interval_ranges(struct snd_interval *i, unsigned int count,
			const struct snd_interval *ranges, unsigned int mask)
{
	unsigned int k;
	struct snd_interval range_union;
	struct snd_interval range;

	if (!count) {
		snd_interval_none(i);
		return -EINVAL;
	}
	snd_interval_any(&range_union);
	range_union.min = UINT_MAX;
	range_union.max = 0;
	for (k = 0; k < count; k++) {
		if (mask && !(mask & (1 << k)))
			continue;
		snd_interval_copy(&range, &ranges[k]);
		if (snd_interval_refine(&range, i) < 0)
			continue;
		if (snd_interval_empty(&range))
			continue;

		if (range.min < range_union.min) {
			range_union.min = range.min;
			range_union.openmin = 1;
		}
		if (range.min == range_union.min && !range.openmin)
			range_union.openmin = 0;
		if (range.max > range_union.max) {
			range_union.max = range.max;
			range_union.openmax = 1;
		}
		if (range.max == range_union.max && !range.openmax)
			range_union.openmax = 0;
	}
	return snd_interval_refine(i, &range_union);
}
EXPORT_SYMBOL(snd_interval_ranges);

static int snd_interval_step(struct snd_interval *i, unsigned int step)
{
	unsigned int n;
	int changed = 0;
	n = i->min % step;
	if (n != 0 || i->openmin) {
		i->min += step - n;
		i->openmin = 0;
		changed = 1;
	}
	n = i->max % step;
	if (n != 0 || i->openmax) {
		i->max -= n;
		i->openmax = 0;
		changed = 1;
	}
	if (snd_interval_checkempty(i)) {
		i->empty = 1;
		return -EINVAL;
	}
	return changed;
}

/* Info constraints helpers */

/**
 * snd_pcm_hw_rule_add - add the hw-constraint rule
 * @runtime: the pcm runtime instance
 * @cond: condition bits
 * @var: the variable to evaluate
 * @func: the evaluation function
 * @private: the private data pointer passed to function
 * @dep: the dependent variables
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
			int var,
			snd_pcm_hw_rule_func_t func, void *private,
			int dep, ...)
{
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	struct snd_pcm_hw_rule *c;
	unsigned int k;
	va_list args;
	va_start(args, dep);
	if (constrs->rules_num >= constrs->rules_all) {
		struct snd_pcm_hw_rule *new;
		unsigned int new_rules = constrs->rules_all + 16;
		new = krealloc(constrs->rules, new_rules * sizeof(*c),
			       GFP_KERNEL);
		if (!new) {
			va_end(args);
			return -ENOMEM;
		}
		constrs->rules = new;
		constrs->rules_all = new_rules;
	}
	c = &constrs->rules[constrs->rules_num];
	c->cond = cond;
	c->func = func;
	c->var = var;
	c->private = private;
	k = 0;
	while (1) {
		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
			va_end(args);
			return -EINVAL;
		}
		c->deps[k++] = dep;
		if (dep < 0)
			break;
		dep = va_arg(args, int);
	}
	constrs->rules_num++;
	va_end(args);
	return 0;
}
EXPORT_SYMBOL(snd_pcm_hw_rule_add);

/**
 * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
 * @runtime: PCM runtime instance
 * @var: hw_params variable to apply the mask
 * @mask: the bitmap mask
 *
 * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
			       u_int32_t mask)
{
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	struct snd_mask *maskp = constrs_mask(constrs, var);
	*maskp->bits &= mask;
	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
	if (*maskp->bits == 0)
		return -EINVAL;
	return 0;
}

/**
 * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
 * @runtime: PCM runtime instance
 * @var: hw_params variable to apply the mask
 * @mask: the 64bit bitmap mask
 *
 * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
				 u_int64_t mask)
{
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	struct snd_mask *maskp = constrs_mask(constrs, var);
	maskp->bits[0] &= (u_int32_t)mask;
	maskp->bits[1] &= (u_int32_t)(mask >> 32);
	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
	if (! maskp->bits[0] && ! maskp->bits[1])
		return -EINVAL;
	return 0;
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);

/**
 * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
 * @runtime: PCM runtime instance
 * @var: hw_params variable to apply the integer constraint
 *
 * Apply the constraint of integer to an interval parameter.
 *
 * Return: Positive if the value is changed, zero if it's not changed, or a
 * negative error code.
 */
int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
{
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	return snd_interval_setinteger(constrs_interval(constrs, var));
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);

/**
 * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
 * @runtime: PCM runtime instance
 * @var: hw_params variable to apply the range
 * @min: the minimal value
 * @max: the maximal value
 * 
 * Apply the min/max range constraint to an interval parameter.
 *
 * Return: Positive if the value is changed, zero if it's not changed, or a
 * negative error code.
 */
int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
				 unsigned int min, unsigned int max)
{
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	struct snd_interval t;
	t.min = min;
	t.max = max;
	t.openmin = t.openmax = 0;
	t.integer = 0;
	return snd_interval_refine(constrs_interval(constrs, var), &t);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);

static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
				struct snd_pcm_hw_rule *rule)
{
	struct snd_pcm_hw_constraint_list *list = rule->private;
	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
}		


/**
 * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
 * @runtime: PCM runtime instance
 * @cond: condition bits
 * @var: hw_params variable to apply the list constraint
 * @l: list
 * 
 * Apply the list of constraints to an interval parameter.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
			       unsigned int cond,
			       snd_pcm_hw_param_t var,
			       const struct snd_pcm_hw_constraint_list *l)
{
	return snd_pcm_hw_rule_add(runtime, cond, var,
				   snd_pcm_hw_rule_list, (void *)l,
				   var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_list);

static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
				  struct snd_pcm_hw_rule *rule)
{
	struct snd_pcm_hw_constraint_ranges *r = rule->private;
	return snd_interval_ranges(hw_param_interval(params, rule->var),
				   r->count, r->ranges, r->mask);
}


/**
 * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
 * @runtime: PCM runtime instance
 * @cond: condition bits
 * @var: hw_params variable to apply the list of range constraints
 * @r: ranges
 *
 * Apply the list of range constraints to an interval parameter.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
				 unsigned int cond,
				 snd_pcm_hw_param_t var,
				 const struct snd_pcm_hw_constraint_ranges *r)
{
	return snd_pcm_hw_rule_add(runtime, cond, var,
				   snd_pcm_hw_rule_ranges, (void *)r,
				   var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);

static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
				   struct snd_pcm_hw_rule *rule)
{
	const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
	unsigned int num = 0, den = 0;
	int err;
	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
				  r->nrats, r->rats, &num, &den);
	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
		params->rate_num = num;
		params->rate_den = den;
	}
	return err;
}

/**
 * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
 * @runtime: PCM runtime instance
 * @cond: condition bits
 * @var: hw_params variable to apply the ratnums constraint
 * @r: struct snd_ratnums constriants
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime, 
				  unsigned int cond,
				  snd_pcm_hw_param_t var,
				  const struct snd_pcm_hw_constraint_ratnums *r)
{
	return snd_pcm_hw_rule_add(runtime, cond, var,
				   snd_pcm_hw_rule_ratnums, (void *)r,
				   var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);

static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
				   struct snd_pcm_hw_rule *rule)
{
	const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
	unsigned int num = 0, den = 0;
	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
				  r->nrats, r->rats, &num, &den);
	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
		params->rate_num = num;
		params->rate_den = den;
	}
	return err;
}

/**
 * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
 * @runtime: PCM runtime instance
 * @cond: condition bits
 * @var: hw_params variable to apply the ratdens constraint
 * @r: struct snd_ratdens constriants
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime, 
				  unsigned int cond,
				  snd_pcm_hw_param_t var,
				  const struct snd_pcm_hw_constraint_ratdens *r)
{
	return snd_pcm_hw_rule_add(runtime, cond, var,
				   snd_pcm_hw_rule_ratdens, (void *)r,
				   var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);

static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
				  struct snd_pcm_hw_rule *rule)
{
	unsigned int l = (unsigned long) rule->private;
	int width = l & 0xffff;
	unsigned int msbits = l >> 16;
	const struct snd_interval *i =
		hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);

	if (!snd_interval_single(i))
		return 0;

	if ((snd_interval_value(i) == width) ||
	    (width == 0 && snd_interval_value(i) > msbits))
		params->msbits = min_not_zero(params->msbits, msbits);

	return 0;
}

/**
 * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
 * @runtime: PCM runtime instance
 * @cond: condition bits
 * @width: sample bits width
 * @msbits: msbits width
 *
 * This constraint will set the number of most significant bits (msbits) if a
 * sample format with the specified width has been select. If width is set to 0
 * the msbits will be set for any sample format with a width larger than the
 * specified msbits.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime, 
				 unsigned int cond,
				 unsigned int width,
				 unsigned int msbits)
{
	unsigned long l = (msbits << 16) | width;
	return snd_pcm_hw_rule_add(runtime, cond, -1,
				    snd_pcm_hw_rule_msbits,
				    (void*) l,
				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);

static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
				struct snd_pcm_hw_rule *rule)
{
	unsigned long step = (unsigned long) rule->private;
	return snd_interval_step(hw_param_interval(params, rule->var), step);
}

/**
 * snd_pcm_hw_constraint_step - add a hw constraint step rule
 * @runtime: PCM runtime instance
 * @cond: condition bits
 * @var: hw_params variable to apply the step constraint
 * @step: step size
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
			       unsigned int cond,
			       snd_pcm_hw_param_t var,
			       unsigned long step)
{
	return snd_pcm_hw_rule_add(runtime, cond, var, 
				   snd_pcm_hw_rule_step, (void *) step,
				   var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_step);

static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
{
	static unsigned int pow2_sizes[] = {
		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
	};
	return snd_interval_list(hw_param_interval(params, rule->var),
				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
}		

/**
 * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
 * @runtime: PCM runtime instance
 * @cond: condition bits
 * @var: hw_params variable to apply the power-of-2 constraint
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
			       unsigned int cond,
			       snd_pcm_hw_param_t var)
{
	return snd_pcm_hw_rule_add(runtime, cond, var, 
				   snd_pcm_hw_rule_pow2, NULL,
				   var, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);

static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
					   struct snd_pcm_hw_rule *rule)
{
	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
	struct snd_interval *rate;

	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
	return snd_interval_list(rate, 1, &base_rate, 0);
}

/**
 * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
 * @runtime: PCM runtime instance
 * @base_rate: the rate at which the hardware does not resample
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
			       unsigned int base_rate)
{
	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
				   SNDRV_PCM_HW_PARAM_RATE,
				   snd_pcm_hw_rule_noresample_func,
				   (void *)(uintptr_t)base_rate,
				   SNDRV_PCM_HW_PARAM_RATE, -1);
}
EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);

static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
				  snd_pcm_hw_param_t var)
{
	if (hw_is_mask(var)) {
		snd_mask_any(hw_param_mask(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
		return;
	}
	if (hw_is_interval(var)) {
		snd_interval_any(hw_param_interval(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
		return;
	}
	snd_BUG();
}

void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
{
	unsigned int k;
	memset(params, 0, sizeof(*params));
	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
		_snd_pcm_hw_param_any(params, k);
	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
		_snd_pcm_hw_param_any(params, k);
	params->info = ~0U;
}
EXPORT_SYMBOL(_snd_pcm_hw_params_any);

/**
 * snd_pcm_hw_param_value - return @params field @var value
 * @params: the hw_params instance
 * @var: parameter to retrieve
 * @dir: pointer to the direction (-1,0,1) or %NULL
 *
 * Return: The value for field @var if it's fixed in configuration space
 * defined by @params. -%EINVAL otherwise.
 */
int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
			   snd_pcm_hw_param_t var, int *dir)
{
	if (hw_is_mask(var)) {
		const struct snd_mask *mask = hw_param_mask_c(params, var);
		if (!snd_mask_single(mask))
			return -EINVAL;
		if (dir)
			*dir = 0;
		return snd_mask_value(mask);
	}
	if (hw_is_interval(var)) {
		const struct snd_interval *i = hw_param_interval_c(params, var);
		if (!snd_interval_single(i))
			return -EINVAL;
		if (dir)
			*dir = i->openmin;
		return snd_interval_value(i);
	}
	return -EINVAL;
}
EXPORT_SYMBOL(snd_pcm_hw_param_value);

void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
				snd_pcm_hw_param_t var)
{
	if (hw_is_mask(var)) {
		snd_mask_none(hw_param_mask(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	} else if (hw_is_interval(var)) {
		snd_interval_none(hw_param_interval(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	} else {
		snd_BUG();
	}
}
EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);

static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
				   snd_pcm_hw_param_t var)
{
	int changed;
	if (hw_is_mask(var))
		changed = snd_mask_refine_first(hw_param_mask(params, var));
	else if (hw_is_interval(var))
		changed = snd_interval_refine_first(hw_param_interval(params, var));
	else
		return -EINVAL;
	if (changed > 0) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}


/**
 * snd_pcm_hw_param_first - refine config space and return minimum value
 * @pcm: PCM instance
 * @params: the hw_params instance
 * @var: parameter to retrieve
 * @dir: pointer to the direction (-1,0,1) or %NULL
 *
 * Inside configuration space defined by @params remove from @var all
 * values > minimum. Reduce configuration space accordingly.
 *
 * Return: The minimum, or a negative error code on failure.
 */
int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm, 
			   struct snd_pcm_hw_params *params, 
			   snd_pcm_hw_param_t var, int *dir)
{
	int changed = _snd_pcm_hw_param_first(params, var);
	if (changed < 0)
		return changed;
	if (params->rmask) {
		int err = snd_pcm_hw_refine(pcm, params);
		if (err < 0)
			return err;
	}
	return snd_pcm_hw_param_value(params, var, dir);
}
EXPORT_SYMBOL(snd_pcm_hw_param_first);

static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
				  snd_pcm_hw_param_t var)
{
	int changed;
	if (hw_is_mask(var))
		changed = snd_mask_refine_last(hw_param_mask(params, var));
	else if (hw_is_interval(var))
		changed = snd_interval_refine_last(hw_param_interval(params, var));
	else
		return -EINVAL;
	if (changed > 0) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}


/**
 * snd_pcm_hw_param_last - refine config space and return maximum value
 * @pcm: PCM instance
 * @params: the hw_params instance
 * @var: parameter to retrieve
 * @dir: pointer to the direction (-1,0,1) or %NULL
 *
 * Inside configuration space defined by @params remove from @var all
 * values < maximum. Reduce configuration space accordingly.
 *
 * Return: The maximum, or a negative error code on failure.
 */
int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm, 
			  struct snd_pcm_hw_params *params,
			  snd_pcm_hw_param_t var, int *dir)
{
	int changed = _snd_pcm_hw_param_last(params, var);
	if (changed < 0)
		return changed;
	if (params->rmask) {
		int err = snd_pcm_hw_refine(pcm, params);
		if (err < 0)
			return err;
	}
	return snd_pcm_hw_param_value(params, var, dir);
}
EXPORT_SYMBOL(snd_pcm_hw_param_last);

static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
				   void *arg)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	unsigned long flags;
	snd_pcm_stream_lock_irqsave(substream, flags);
	if (snd_pcm_running(substream) &&
	    snd_pcm_update_hw_ptr(substream) >= 0)
		runtime->status->hw_ptr %= runtime->buffer_size;
	else {
		runtime->status->hw_ptr = 0;
		runtime->hw_ptr_wrap = 0;
	}
	snd_pcm_stream_unlock_irqrestore(substream, flags);
	return 0;
}

static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
					  void *arg)
{
	struct snd_pcm_channel_info *info = arg;
	struct snd_pcm_runtime *runtime = substream->runtime;
	int width;
	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
		info->offset = -1;
		return 0;
	}
	width = snd_pcm_format_physical_width(runtime->format);
	if (width < 0)
		return width;
	info->offset = 0;
	switch (runtime->access) {
	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
		info->first = info->channel * width;
		info->step = runtime->channels * width;
		break;
	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
	{
		size_t size = runtime->dma_bytes / runtime->channels;
		info->first = info->channel * size * 8;
		info->step = width;
		break;
	}
	default:
		snd_BUG();
		break;
	}
	return 0;
}

static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
				       void *arg)
{
	struct snd_pcm_hw_params *params = arg;
	snd_pcm_format_t format;
	int channels;
	ssize_t frame_size;

	params->fifo_size = substream->runtime->hw.fifo_size;
	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
		format = params_format(params);
		channels = params_channels(params);
		frame_size = snd_pcm_format_size(format, channels);
		if (frame_size > 0)
			params->fifo_size /= frame_size;
	}
	return 0;
}

/**
 * snd_pcm_lib_ioctl - a generic PCM ioctl callback
 * @substream: the pcm substream instance
 * @cmd: ioctl command
 * @arg: ioctl argument
 *
 * Processes the generic ioctl commands for PCM.
 * Can be passed as the ioctl callback for PCM ops.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
		      unsigned int cmd, void *arg)
{
	switch (cmd) {
	case SNDRV_PCM_IOCTL1_RESET:
		return snd_pcm_lib_ioctl_reset(substream, arg);
	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
		return snd_pcm_lib_ioctl_channel_info(substream, arg);
	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
	}
	return -ENXIO;
}
EXPORT_SYMBOL(snd_pcm_lib_ioctl);

/**
 * snd_pcm_period_elapsed - update the pcm status for the next period
 * @substream: the pcm substream instance
 *
 * This function is called from the interrupt handler when the
 * PCM has processed the period size.  It will update the current
 * pointer, wake up sleepers, etc.
 *
 * Even if more than one periods have elapsed since the last call, you
 * have to call this only once.
 */
void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime;
	unsigned long flags;

	if (snd_BUG_ON(!substream))
		return;

	snd_pcm_stream_lock_irqsave(substream, flags);
	if (PCM_RUNTIME_CHECK(substream))
		goto _unlock;
	runtime = substream->runtime;

	if (!snd_pcm_running(substream) ||
	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
		goto _end;

#ifdef CONFIG_SND_PCM_TIMER
	if (substream->timer_running)
		snd_timer_interrupt(substream->timer, 1);
#endif
 _end:
	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
 _unlock:
	snd_pcm_stream_unlock_irqrestore(substream, flags);
}
EXPORT_SYMBOL(snd_pcm_period_elapsed);

/*
 * Wait until avail_min data becomes available
 * Returns a negative error code if any error occurs during operation.
 * The available space is stored on availp.  When err = 0 and avail = 0
 * on the capture stream, it indicates the stream is in DRAINING state.
 */
static int wait_for_avail(struct snd_pcm_substream *substream,
			      snd_pcm_uframes_t *availp)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
	wait_queue_entry_t wait;
	int err = 0;
	snd_pcm_uframes_t avail = 0;
	long wait_time, tout;

	init_waitqueue_entry(&wait, current);
	set_current_state(TASK_INTERRUPTIBLE);
	add_wait_queue(&runtime->tsleep, &wait);

	if (runtime->no_period_wakeup)
		wait_time = MAX_SCHEDULE_TIMEOUT;
	else {
		/* use wait time from substream if available */
		if (substream->wait_time) {
			wait_time = substream->wait_time;
		} else {
			wait_time = 10;

			if (runtime->rate) {
				long t = runtime->period_size * 2 /
					 runtime->rate;
				wait_time = max(t, wait_time);
			}
			wait_time = msecs_to_jiffies(wait_time * 1000);
		}
	}

	for (;;) {
		if (signal_pending(current)) {
			err = -ERESTARTSYS;
			break;
		}

		/*
		 * We need to check if space became available already
		 * (and thus the wakeup happened already) first to close
		 * the race of space already having become available.
		 * This check must happen after been added to the waitqueue
		 * and having current state be INTERRUPTIBLE.
		 */
		avail = snd_pcm_avail(substream);
		if (avail >= runtime->twake)
			break;
		snd_pcm_stream_unlock_irq(substream);

		tout = schedule_timeout(wait_time);

		snd_pcm_stream_lock_irq(substream);
		set_current_state(TASK_INTERRUPTIBLE);
		switch (runtime->status->state) {
		case SNDRV_PCM_STATE_SUSPENDED:
			err = -ESTRPIPE;
			goto _endloop;
		case SNDRV_PCM_STATE_XRUN:
			err = -EPIPE;
			goto _endloop;
		case SNDRV_PCM_STATE_DRAINING:
			if (is_playback)
				err = -EPIPE;
			else 
				avail = 0; /* indicate draining */
			goto _endloop;
		case SNDRV_PCM_STATE_OPEN:
		case SNDRV_PCM_STATE_SETUP:
		case SNDRV_PCM_STATE_DISCONNECTED:
			err = -EBADFD;
			goto _endloop;
		case SNDRV_PCM_STATE_PAUSED:
			continue;
		}
		if (!tout) {
			pcm_dbg(substream->pcm,
				"%s write error (DMA or IRQ trouble?)\n",
				is_playback ? "playback" : "capture");
			err = -EIO;
			break;
		}
	}
 _endloop:
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&runtime->tsleep, &wait);
	*availp = avail;
	return err;
}
	
typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
			      int channel, unsigned long hwoff,
			      void *buf, unsigned long bytes);

typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
			  snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f);

/* calculate the target DMA-buffer position to be written/read */
static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
			   int channel, unsigned long hwoff)
{
	return runtime->dma_area + hwoff +
		channel * (runtime->dma_bytes / runtime->channels);
}

/* default copy_user ops for write; used for both interleaved and non- modes */
static int default_write_copy(struct snd_pcm_substream *substream,
			      int channel, unsigned long hwoff,
			      void *buf, unsigned long bytes)
{
	if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff),
			   (void __user *)buf, bytes))
		return -EFAULT;
	return 0;
}

/* default copy_kernel ops for write */
static int default_write_copy_kernel(struct snd_pcm_substream *substream,
				     int channel, unsigned long hwoff,
				     void *buf, unsigned long bytes)
{
	memcpy(get_dma_ptr(substream->runtime, channel, hwoff), buf, bytes);
	return 0;
}

/* fill silence instead of copy data; called as a transfer helper
 * from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
 * a NULL buffer is passed
 */
static int fill_silence(struct snd_pcm_substream *substream, int channel,
			unsigned long hwoff, void *buf, unsigned long bytes)
{
	struct snd_pcm_runtime *runtime = substream->runtime;

	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
		return 0;
	if (substream->ops->fill_silence)
		return substream->ops->fill_silence(substream, channel,
						    hwoff, bytes);

	snd_pcm_format_set_silence(runtime->format,
				   get_dma_ptr(runtime, channel, hwoff),
				   bytes_to_samples(runtime, bytes));
	return 0;
}

/* default copy_user ops for read; used for both interleaved and non- modes */
static int default_read_copy(struct snd_pcm_substream *substream,
			     int channel, unsigned long hwoff,
			     void *buf, unsigned long bytes)
{
	if (copy_to_user((void __user *)buf,
			 get_dma_ptr(substream->runtime, channel, hwoff),
			 bytes))
		return -EFAULT;
	return 0;
}

/* default copy_kernel ops for read */
static int default_read_copy_kernel(struct snd_pcm_substream *substream,
				    int channel, unsigned long hwoff,
				    void *buf, unsigned long bytes)
{
	memcpy(buf, get_dma_ptr(substream->runtime, channel, hwoff), bytes);
	return 0;
}

/* call transfer function with the converted pointers and sizes;
 * for interleaved mode, it's one shot for all samples
 */
static int interleaved_copy(struct snd_pcm_substream *substream,
			    snd_pcm_uframes_t hwoff, void *data,
			    snd_pcm_uframes_t off,
			    snd_pcm_uframes_t frames,
			    pcm_transfer_f transfer)
{
	struct snd_pcm_runtime *runtime = substream->runtime;

	/* convert to bytes */
	hwoff = frames_to_bytes(runtime, hwoff);
	off = frames_to_bytes(runtime, off);
	frames = frames_to_bytes(runtime, frames);
	return transfer(substream, 0, hwoff, data + off, frames);
}

/* call transfer function with the converted pointers and sizes for each
 * non-interleaved channel; when buffer is NULL, silencing instead of copying
 */
static int noninterleaved_copy(struct snd_pcm_substream *substream,
			       snd_pcm_uframes_t hwoff, void *data,
			       snd_pcm_uframes_t off,
			       snd_pcm_uframes_t frames,
			       pcm_transfer_f transfer)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int channels = runtime->channels;
	void **bufs = data;
	int c, err;

	/* convert to bytes; note that it's not frames_to_bytes() here.
	 * in non-interleaved mode, we copy for each channel, thus
	 * each copy is n_samples bytes x channels = whole frames.
	 */
	off = samples_to_bytes(runtime, off);
	frames = samples_to_bytes(runtime, frames);
	hwoff = samples_to_bytes(runtime, hwoff);
	for (c = 0; c < channels; ++c, ++bufs) {
		if (!data || !*bufs)
			err = fill_silence(substream, c, hwoff, NULL, frames);
		else
			err = transfer(substream, c, hwoff, *bufs + off,
				       frames);
		if (err < 0)
			return err;
	}
	return 0;
}

/* fill silence on the given buffer position;
 * called from snd_pcm_playback_silence()
 */
static int fill_silence_frames(struct snd_pcm_substream *substream,
			       snd_pcm_uframes_t off, snd_pcm_uframes_t frames)
{
	if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
	    substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
		return interleaved_copy(substream, off, NULL, 0, frames,
					fill_silence);
	else
		return noninterleaved_copy(substream, off, NULL, 0, frames,
					   fill_silence);
}

/* sanity-check for read/write methods */
static int pcm_sanity_check(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime;
	if (PCM_RUNTIME_CHECK(substream))
		return -ENXIO;
	runtime = substream->runtime;
	if (snd_BUG_ON(!substream->ops->copy_user && !runtime->dma_area))
		return -EINVAL;
	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
		return -EBADFD;
	return 0;
}

static int pcm_accessible_state(struct snd_pcm_runtime *runtime)
{
	switch (runtime->status->state) {
	case SNDRV_PCM_STATE_PREPARED:
	case SNDRV_PCM_STATE_RUNNING:
	case SNDRV_PCM_STATE_PAUSED:
		return 0;
	case SNDRV_PCM_STATE_XRUN:
		return -EPIPE;
	case SNDRV_PCM_STATE_SUSPENDED:
		return -ESTRPIPE;
	default:
		return -EBADFD;
	}
}

/* update to the given appl_ptr and call ack callback if needed;
 * when an error is returned, take back to the original value
 */
int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
			   snd_pcm_uframes_t appl_ptr)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr;
	int ret;

	if (old_appl_ptr == appl_ptr)
		return 0;

	runtime->control->appl_ptr = appl_ptr;
	if (substream->ops->ack) {
		ret = substream->ops->ack(substream);
		if (ret < 0) {
			runtime->control->appl_ptr = old_appl_ptr;
			return ret;
		}
	}

	trace_applptr(substream, old_appl_ptr, appl_ptr);

	return 0;
}

/* the common loop for read/write data */
snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
				     void *data, bool interleaved,
				     snd_pcm_uframes_t size, bool in_kernel)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_uframes_t xfer = 0;
	snd_pcm_uframes_t offset = 0;
	snd_pcm_uframes_t avail;
	pcm_copy_f writer;
	pcm_transfer_f transfer;
	bool nonblock;
	bool is_playback;
	int err;

	err = pcm_sanity_check(substream);
	if (err < 0)
		return err;

	is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
	if (interleaved) {
		if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
		    runtime->channels > 1)
			return -EINVAL;
		writer = interleaved_copy;
	} else {
		if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
			return -EINVAL;
		writer = noninterleaved_copy;
	}

	if (!data) {
		if (is_playback)
			transfer = fill_silence;
		else
			return -EINVAL;
	} else if (in_kernel) {
		if (substream->ops->copy_kernel)
			transfer = substream->ops->copy_kernel;
		else
			transfer = is_playback ?
				default_write_copy_kernel : default_read_copy_kernel;
	} else {
		if (substream->ops->copy_user)
			transfer = (pcm_transfer_f)substream->ops->copy_user;
		else
			transfer = is_playback ?
				default_write_copy : default_read_copy;
	}

	if (size == 0)
		return 0;

	nonblock = !!(substream->f_flags & O_NONBLOCK);

	snd_pcm_stream_lock_irq(substream);
	err = pcm_accessible_state(runtime);
	if (err < 0)
		goto _end_unlock;

	runtime->twake = runtime->control->avail_min ? : 1;
	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
		snd_pcm_update_hw_ptr(substream);

	/*
	 * If size < start_threshold, wait indefinitely. Another
	 * thread may start capture
	 */
	if (!is_playback &&
	    runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
	    size >= runtime->start_threshold) {
		err = snd_pcm_start(substream);
		if (err < 0)
			goto _end_unlock;
	}

	avail = snd_pcm_avail(substream);

	while (size > 0) {
		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
		snd_pcm_uframes_t cont;
		if (!avail) {
			if (!is_playback &&
			    runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
				goto _end_unlock;
			}
			if (nonblock) {
				err = -EAGAIN;
				goto _end_unlock;
			}
			runtime->twake = min_t(snd_pcm_uframes_t, size,
					runtime->control->avail_min ? : 1);
			err = wait_for_avail(substream, &avail);
			if (err < 0)
				goto _end_unlock;
			if (!avail)
				continue; /* draining */
		}
		frames = size > avail ? avail : size;
		appl_ptr = READ_ONCE(runtime->control->appl_ptr);
		appl_ofs = appl_ptr % runtime->buffer_size;
		cont = runtime->buffer_size - appl_ofs;
		if (frames > cont)
			frames = cont;
		if (snd_BUG_ON(!frames)) {
			err = -EINVAL;
			goto _end_unlock;
		}
		snd_pcm_stream_unlock_irq(substream);
		err = writer(substream, appl_ofs, data, offset, frames,
			     transfer);
		snd_pcm_stream_lock_irq(substream);
		if (err < 0)
			goto _end_unlock;
		err = pcm_accessible_state(runtime);
		if (err < 0)
			goto _end_unlock;
		appl_ptr += frames;
		if (appl_ptr >= runtime->boundary)
			appl_ptr -= runtime->boundary;
		err = pcm_lib_apply_appl_ptr(substream, appl_ptr);
		if (err < 0)
			goto _end_unlock;

		offset += frames;
		size -= frames;
		xfer += frames;
		avail -= frames;
		if (is_playback &&
		    runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
			err = snd_pcm_start(substream);
			if (err < 0)
				goto _end_unlock;
		}
	}
 _end_unlock:
	runtime->twake = 0;
	if (xfer > 0 && err >= 0)
		snd_pcm_update_state(substream, runtime);
	snd_pcm_stream_unlock_irq(substream);
	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
}
EXPORT_SYMBOL(__snd_pcm_lib_xfer);

/*
 * standard channel mapping helpers
 */

/* default channel maps for multi-channel playbacks, up to 8 channels */
const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
	{ .channels = 1,
	  .map = { SNDRV_CHMAP_MONO } },
	{ .channels = 2,
	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
	{ .channels = 4,
	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
	{ .channels = 6,
	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
	{ .channels = 8,
	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
	{ }
};
EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);

/* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
	{ .channels = 1,
	  .map = { SNDRV_CHMAP_MONO } },
	{ .channels = 2,
	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
	{ .channels = 4,
	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
	{ .channels = 6,
	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
	{ .channels = 8,
	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
	{ }
};
EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);

static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
{
	if (ch > info->max_channels)
		return false;
	return !info->channel_mask || (info->channel_mask & (1U << ch));
}

static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
			      struct snd_ctl_elem_info *uinfo)
{
	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);

	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
	uinfo->count = 0;
	uinfo->count = info->max_channels;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
	return 0;
}

/* get callback for channel map ctl element
 * stores the channel position firstly matching with the current channels
 */
static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
			     struct snd_ctl_elem_value *ucontrol)
{
	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
	struct snd_pcm_substream *substream;
	const struct snd_pcm_chmap_elem *map;

	if (!info->chmap)
		return -EINVAL;
	substream = snd_pcm_chmap_substream(info, idx);
	if (!substream)
		return -ENODEV;
	memset(ucontrol->value.integer.value, 0,
	       sizeof(ucontrol->value.integer.value));
	if (!substream->runtime)
		return 0; /* no channels set */
	for (map = info->chmap; map->channels; map++) {
		int i;
		if (map->channels == substream->runtime->channels &&
		    valid_chmap_channels(info, map->channels)) {
			for (i = 0; i < map->channels; i++)
				ucontrol->value.integer.value[i] = map->map[i];
			return 0;
		}
	}
	return -EINVAL;
}

/* tlv callback for channel map ctl element
 * expands the pre-defined channel maps in a form of TLV
 */
static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
			     unsigned int size, unsigned int __user *tlv)
{
	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
	const struct snd_pcm_chmap_elem *map;
	unsigned int __user *dst;
	int c, count = 0;

	if (!info->chmap)
		return -EINVAL;
	if (size < 8)
		return -ENOMEM;
	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
		return -EFAULT;
	size -= 8;
	dst = tlv + 2;
	for (map = info->chmap; map->channels; map++) {
		int chs_bytes = map->channels * 4;
		if (!valid_chmap_channels(info, map->channels))
			continue;
		if (size < 8)
			return -ENOMEM;
		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
		    put_user(chs_bytes, dst + 1))
			return -EFAULT;
		dst += 2;
		size -= 8;
		count += 8;
		if (size < chs_bytes)
			return -ENOMEM;
		size -= chs_bytes;
		count += chs_bytes;
		for (c = 0; c < map->channels; c++) {
			if (put_user(map->map[c], dst))
				return -EFAULT;
			dst++;
		}
	}
	if (put_user(count, tlv + 1))
		return -EFAULT;
	return 0;
}

static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
{
	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
	info->pcm->streams[info->stream].chmap_kctl = NULL;
	kfree(info);
}

/**
 * snd_pcm_add_chmap_ctls - create channel-mapping control elements
 * @pcm: the assigned PCM instance
 * @stream: stream direction
 * @chmap: channel map elements (for query)
 * @max_channels: the max number of channels for the stream
 * @private_value: the value passed to each kcontrol's private_value field
 * @info_ret: store struct snd_pcm_chmap instance if non-NULL
 *
 * Create channel-mapping control elements assigned to the given PCM stream(s).
 * Return: Zero if successful, or a negative error value.
 */
int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
			   const struct snd_pcm_chmap_elem *chmap,
			   int max_channels,
			   unsigned long private_value,
			   struct snd_pcm_chmap **info_ret)
{
	struct snd_pcm_chmap *info;
	struct snd_kcontrol_new knew = {
		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
		.access = SNDRV_CTL_ELEM_ACCESS_READ |
			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
		.info = pcm_chmap_ctl_info,
		.get = pcm_chmap_ctl_get,
		.tlv.c = pcm_chmap_ctl_tlv,
	};
	int err;

	if (WARN_ON(pcm->streams[stream].chmap_kctl))
		return -EBUSY;
	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;
	info->pcm = pcm;
	info->stream = stream;
	info->chmap = chmap;
	info->max_channels = max_channels;
	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
		knew.name = "Playback Channel Map";
	else
		knew.name = "Capture Channel Map";
	knew.device = pcm->device;
	knew.count = pcm->streams[stream].substream_count;
	knew.private_value = private_value;
	info->kctl = snd_ctl_new1(&knew, info);
	if (!info->kctl) {
		kfree(info);
		return -ENOMEM;
	}
	info->kctl->private_free = pcm_chmap_ctl_private_free;
	err = snd_ctl_add(pcm->card, info->kctl);
	if (err < 0)
		return err;
	pcm->streams[stream].chmap_kctl = info->kctl;
	if (info_ret)
		*info_ret = info;
	return 0;
}
EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);