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2013-06-19ACPI / video: ignore BIOS initial backlight value for HP Pavilion g6Ash Willis
commit 780a6ec640a3fed671fc2c40e4dd30c03eca3ac3 upstream. This patch addresses kernel bug 56661. BIOS reports an incorrect backlight value, causing the driver to switch off the backlight completely during startup. This patch ignores the incorrect value from BIOS. References: https://bugzilla.kernel.org/show_bug.cgi?id=56661 Signed-off-by: Ash Willis <ashwillis@programmer.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-06-19ACPI / video: ignore BIOS initial backlight value for HP m4Alex Hung
commit fedbe9bc6fd3e14b1ffbb3dac407777ac4a3650c upstream. On HP m4 lapops, BIOS reports minimum backlight on boot and causes backlight to dim completely. This ignores the initial backlight values and set to max brightness. References: https://bugs.launchpad.net/bugs/1184501 Signed-off-by: Alex Hung <alex.hung@canonical.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-06-19ACPI video: ignore BIOS initial backlight value for HP 1000Alex Hung
commit 4ef366c583d6180b1c951147869ee5a3038834f2 upstream. On HP 1000 lapops, BIOS reports minimum backlight on boot and causes backlight to dim completely. This ignores the initial backlight values and set to max brightness. References:: https://bugs.launchpad.net/bugs/1167760 Signed-off-by: Alex Hung <alex.hung@canonical.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-06-19ACPI video: ignore BIOS backlight value for HP dm4Gustavo Maciel Dias Vieira
commit 771d09b3c4c45d4d534a83a68e6331b97fd82e15 upstream. On a HP Pavilion dm4 laptop the BIOS sets minimum backlight on boot, completely dimming the screen. Ignore this initial value for this machine. Signed-off-by: Gustavo Maciel Dias Vieira <gustavo@sagui.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-05-30ACPI / video: Add "Asus UL30A" to ACPI video detect blacklistBastian Triller
commit c8f6d8351ba8c89d5cd4c562552ec7ec29274e31 upstream. Like on UL30VT, the ACPI video driver can't control backlight correctly on Asus UL30A. Vendor driver (asus-laptop) can work. This patch is to add "Asus UL30A" to ACPI video detect blacklist in order to use asus-laptop for video control on the "Asus UL30A" rather than ACPI video driver. Signed-off-by: Bastian Triller <bastian.triller@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-05-30ACPI / EC: Restart transaction even when the IBF flag setLan Tianyu
commit 28fe5c825f8e15744d04c7c1b8df197950923ecd upstream. The EC driver works abnormally with IBF flag always set. IBF means "The host has written a byte of data to the command or data port, but the embedded controller has not yet read it". If IBF is set in the EC status and not cleared, this will cause all subsequent EC requests to fail with a timeout error. Change the EC driver so that it doesn't refuse to restart a transaction if IBF is set in the status. Also increase the number of transaction restarts to 5, as it turns out that 2 is not sufficient in some cases. This bug happens on several different machines (Asus V1S, Dell Latitude E6530, Samsung R719, Acer Aspire 5930G, Sony Vaio SR19VN and others). [rjw: Changelog] References: https://bugzilla.kernel.org/show_bug.cgi?id=14733 References: https://bugzilla.kernel.org/show_bug.cgi?id=15560 References: https://bugzilla.kernel.org/show_bug.cgi?id=15946 References: https://bugzilla.kernel.org/show_bug.cgi?id=42945 References: https://bugzilla.kernel.org/show_bug.cgi?id=48221 Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-05-30ACPICA: Fix possible buffer overflow during a field unit read operationBob Moore
commit 61388f9e5d93053cf399a356414f31f9b4814c6d upstream. Can only happen under these conditions: 1) The DSDT version is 1, meaning integers are 32-bits. 2) The field is between 33 and 64 bits long. It applies cleanly back to ACPICA 20100806+ (Linux v2.6.37+). Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-05-13PCI / ACPI: Don't query OSC support with all possible controlsYinghai Lu
commit 545d6e189a41c94c11f55045a771118eccc9d9eb upstream. Found problem on system that firmware that could handle pci aer. Firmware get error reporting after pci injecting error, before os boots. But after os boots, firmware can not get report anymore, even pci=noaer is passed. Root cause: BIOS _OSC has problem with query bit checking. It turns out that BIOS vendor is copying example code from ACPI Spec. In ACPI Spec 5.0, page 290: If (Not(And(CDW1,1))) // Query flag clear? { // Disable GPEs for features granted native control. If (And(CTRL,0x01)) // Hot plug control granted? { Store(0,HPCE) // clear the hot plug SCI enable bit Store(1,HPCS) // clear the hot plug SCI status bit } ... } When Query flag is set, And(CDW1,1) will be 1, Not(1) will return 0xfffffffe. So it will get into code path that should be for control set only. BIOS acpi code should be changed to "If (LEqual(And(CDW1,1), 0)))" Current kernel code is using _OSC query to notify firmware about support from OS and then use _OSC to set control bits. During query support, current code is using all possible controls. So will execute code that should be only for control set stage. That will have problem when pci=noaer or aer firmware_first is used. As firmware have that control set for os aer already in query support stage, but later will not os aer handling. We should avoid passing all possible controls, just use osc_control_set instead. That should workaround BIOS bugs with affected systems on the field as more bios vendors are copying sample code from ACPI spec. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-03-06ACPI: Add DMI entry for Sony VGN-FW41E_HJoseph Salisbury
commit 66f2fda93b67fa744d406e6dcf443f67bac204b6 upstream. This patch adds a quirk to allow the Sony VGN-FW41E_H to suspend/resume properly. References: http://bugs.launchpad.net/bugs/1113547 Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-02-06efi: Make 'efi_enabled' a function to query EFI facilitiesMatt Fleming
commit 83e68189745ad931c2afd45d8ee3303929233e7f upstream. Originally 'efi_enabled' indicated whether a kernel was booted from EFI firmware. Over time its semantics have changed, and it now indicates whether or not we are booted on an EFI machine with bit-native firmware, e.g. 64-bit kernel with 64-bit firmware. The immediate motivation for this patch is the bug report at, https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557 which details how running a platform driver on an EFI machine that is designed to run under BIOS can cause the machine to become bricked. Also, the following report, https://bugzilla.kernel.org/show_bug.cgi?id=47121 details how running said driver can also cause Machine Check Exceptions. Drivers need a new means of detecting whether they're running on an EFI machine, as sadly the expression, if (!efi_enabled) hasn't been a sufficient condition for quite some time. Users actually want to query 'efi_enabled' for different reasons - what they really want access to is the list of available EFI facilities. For instance, the x86 reboot code needs to know whether it can invoke the ResetSystem() function provided by the EFI runtime services, while the ACPI OSL code wants to know whether the EFI config tables were mapped successfully. There are also checks in some of the platform driver code to simply see if they're running on an EFI machine (which would make it a bad idea to do BIOS-y things). This patch is a prereq for the samsung-laptop fix patch. Cc: David Airlie <airlied@linux.ie> Cc: Corentin Chary <corentincj@iksaif.net> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Olof Johansson <olof@lixom.net> Cc: Peter Jones <pjones@redhat.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Steve Langasek <steve.langasek@canonical.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Konrad Rzeszutek Wilk <konrad@kernel.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> [bwh: Backported to 3.2: - Adjust context (a lot) - Add efi_is_native() function from commit 5189c2a7c776 ('x86: efi: Turn off efi_enabled after setup on mixed fw/kernel') - Make efi_init() bail out when booted non-native, as it would previously not be called in this case - Drop inapplicable changes to start_kernel()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-02-06ACPI / processor: Get power info before updating the C-statesThomas Schlichter
commit f427e5f1cf75bba84cccdac1d8a90552d9ae1065 upstream. acpi_processor_get_power_info() has to be called before acpi_processor_setup_cpuidle_states() to have the latest information available. This fixes the missing C-state information after AC-->DC transition. Signed-off-by: Thomas Schlichter <thomas.schlichter@web.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-02-06ACPI / cpuidle: Fix NULL pointer issues when cpuidle is disabledKonrad Rzeszutek Wilk
commit b88a634a903d9670aa5f2f785aa890628ce0dece upstream. If cpuidle is disabled, that means that: per_cpu(acpi_cpuidle_device, pr->id) is set to NULL as the acpi_processor_power_init ends up failing at retval = cpuidle_register_driver(&acpi_idle_driver) (in acpi_processor_power_init) and never sets the per_cpu idle device. So when acpi_processor_hotplug on CPU online notification tries to reference said device it crashes: cpu 3 spinlock event irq 62 BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: [<ffffffff81381013>] acpi_processor_setup_cpuidle_cx+0x3f/0x105 PGD a259b067 PUD ab38b067 PMD 0 Oops: 0002 [#1] SMP odules linked in: dm_multipath dm_mod xen_evtchn iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi libcrc32c crc32c nouveau mxm_wmi wmi radeon ttm sg sr_mod sd_mod cdrom ata_generic ata_piix libata crc32c_intel scsi_mod atl1c i915 fbcon tileblit font bitblit softcursor drm_kms_helper video xen_blkfront xen_netfront fb_sys_fops sysimgblt sysfillrect syscopyarea xenfs xen_privcmd mperf CPU 1 Pid: 3047, comm: bash Not tainted 3.8.0-rc3upstream-00250-g165c029 #1 MSI MS-7680/H61M-P23 (MS-7680) RIP: e030:[<ffffffff81381013>] [<ffffffff81381013>] acpi_processor_setup_cpuidle_cx+0x3f/0x105 RSP: e02b:ffff88001742dca8 EFLAGS: 00010202 RAX: 0000000000010be9 RBX: ffff8800a0a61800 RCX: ffff880105380000 RDX: 0000000000000003 RSI: 0000000000000200 RDI: ffff8800a0a61800 RBP: ffff88001742dce8 R08: ffffffff81812360 R09: 0000000000000200 R10: aaaaaaaaaaaaaaaa R11: 0000000000000001 R12: ffff8800a0a61800 R13: 00000000ffffff01 R14: 0000000000000000 R15: ffffffff81a907a0 FS: 00007fd6942f7700(0000) GS:ffff880105280000(0000) knlGS:0000000000000000 CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000004 CR3: 00000000a6773000 CR4: 0000000000042660 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process bash (pid: 3047, threadinfo ffff88001742c000, task ffff880017944000) Stack: 0000000000000150 ffff880100f59e00 ffff88001742dcd8 ffff8800a0a61800 0000000000000000 00000000ffffff01 0000000000000000 ffffffff81a907a0 ffff88001742dd18 ffffffff813815b1 ffff88001742dd08 ffffffff810ae336 Call Trace: [<ffffffff813815b1>] acpi_processor_hotplug+0x7c/0x9f [<ffffffff810ae336>] ? schedule_delayed_work_on+0x16/0x20 [<ffffffff8137ee8f>] acpi_cpu_soft_notify+0x90/0xca [<ffffffff8166023d>] notifier_call_chain+0x4d/0x70 [<ffffffff810bc369>] __raw_notifier_call_chain+0x9/0x10 [<ffffffff81094a4b>] __cpu_notify+0x1b/0x30 [<ffffffff81652cf7>] _cpu_up+0x103/0x14b [<ffffffff81652e18>] cpu_up+0xd9/0xec [<ffffffff8164a254>] store_online+0x94/0xd0 [<ffffffff814122fb>] dev_attr_store+0x1b/0x20 [<ffffffff81216404>] sysfs_write_file+0xf4/0x170 This patch fixes it. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-16ACPI : do not use Lid and Sleep button for S5 wakeupZhang Rui
commit b7e383046c2c7c13ad928cd7407eafff758ddd4b upstream. When system enters power off, the _PSW of Lid device is enabled. But this may cause the system to reboot instead of power off. A proper way to fix this is to always disable lid wakeup capability for S5. References: https://bugzilla.kernel.org/show_bug.cgi?id=35262 Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-16ACPI / scan: Do not use dummy HID for system bus ACPI nodesRafael J. Wysocki
commit 4f5f64cf0cc916220aaa055992e31195470cfe37 upstream. At one point acpi_device_set_id() checks if acpi_device_hid(device) returns NULL, but that never happens, so system bus devices with an empty list of PNP IDs are given the dummy HID ("device") instead of the "system bus HID" ("LNXSYBUS"). Fix the code to use the right check. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-03ACPI / video: ignore BIOS initial backlight value for HP Folio 13-2000Zhang Rui
commit 129ff8f8d58297b04f47b5d6fad81aa2d08404e1 upstream. Or else the laptop will boot with a dimmed screen. References: https://bugzilla.kernel.org/show_bug.cgi?id=51141 Tested-by: Stefan Nagy <public@stefan-nagy.at> Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-03ACPI / video: Add "Asus UL30VT" to ACPI video detect blacklistLan Tianyu
commit d0c2ce16bec0afa6013b4c5220ca4c9c67210215 upstream. The ACPI video driver can't control backlight correctly on Asus UL30VT. Vendor driver (asus-laptop) can work. This patch is to add "Asus UL30VT" to ACPI video detect blacklist in order to use asus-laptop for video control on the "Asus UL30VT" rather than ACPI video driver. References: https://bugzilla.kernel.org/show_bug.cgi?id=32592 Reported-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-03acpi/video_detect: blacklist samsung x360Corentin Chary
commit 084940d5b101e9ca91a689eb5048151b14076839 upstream. On Samsung X360, the BIOS will set a flag (VDRV) if the generic ACPI backlight device is used. This flag will definitively break the backlight interface (even the vendor interface) untill next reboot. It's why we should prevent video.ko from being used here and we can't rely on a later call to acpi_video_unregister(). Signed-off-by: Corentin Chary <corentin.chary@gmail.com> Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-03ACPI: do acpisleep dmi check when CONFIG_ACPI_SLEEP is setZhang Rui
commit 0ac1b1d7b7424cd6f129b5454b504b3cae746f0e upstream. The current acpisleep DMI checks only run when CONFIG_SUSPEND is set. And this may break hibernation on some platforms when CONFIG_SUSPEND is cleared. Move acpisleep DMI check into #ifdef CONFIG_ACPI_SLEEP instead. [rjw: Added acpi_sleep_dmi_check() and rebased on top of earlier patches adding entries to acpisleep_dmi_table[].] References: https://bugzilla.kernel.org/show_bug.cgi?id=45921 Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-03ACPI / PM: Add Sony Vaio VPCEB1S1E to nonvs blacklist.Lan Tianyu
commit 876ab79055019e248508cfd0dee7caa3c0c831ed upstream. Sony Vaio VPCEB1S1E does not resume correctly without acpi_sleep=nonvs, so add it to the ACPI sleep blacklist. References: https://bugzilla.kernel.org/show_bug.cgi?id=48781 Reported-by: Sébastien Wilmet <swilmet@gnome.org> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-03ACPI / battery: Correct battery capacity values on ThinkpadsKamil Iskra
commit 4000e626156935dfb626321ce09cae2c833eabbb upstream. Add a quirk to correctly report battery capacity on 2010 and 2011 Lenovo Thinkpad models. The affected models that I tested (x201, t410, t410s, and x220) exhibit a problem where, when battery capacity reporting unit is mAh, the values being reported are wrong. Pre-2010 and 2012 models appear to always report in mWh and are thus unaffected. Also, in mid-2012 Lenovo issued a BIOS update for the 2011 models that fixes the issue (tested on x220 with a post-1.29 BIOS). No such update is available for the 2010 models, so those still need this patch. Problem description: for some reason, the affected Thinkpads switch the reporting unit between mAh and mWh; generally, mAh is used when a laptop is plugged in and mWh when it's unplugged, although a suspend/resume or rmmod/modprobe is needed for the switch to take effect. The values reported in mAh are *always* wrong. This does not appear to be a kernel regression; I believe that the values were never reported correctly. I tested back to kernel 2.6.34, with multiple machines and BIOS versions. Simply plugging a laptop into mains before turning it on is enough to reproduce the problem. Here's a sample /proc/acpi/battery/BAT0/info from Thinkpad x220 (before a BIOS update) with a 4-cell battery: present: yes design capacity: 2886 mAh last full capacity: 2909 mAh battery technology: rechargeable design voltage: 14800 mV design capacity warning: 145 mAh design capacity low: 13 mAh cycle count: 0 capacity granularity 1: 1 mAh capacity granularity 2: 1 mAh model number: 42T4899 serial number: 21064 battery type: LION OEM info: SANYO Once the laptop switches the unit to mWh (unplug from mains, suspend, resume), the output changes to: present: yes design capacity: 28860 mWh last full capacity: 29090 mWh battery technology: rechargeable design voltage: 14800 mV design capacity warning: 1454 mWh design capacity low: 200 mWh cycle count: 0 capacity granularity 1: 1 mWh capacity granularity 2: 1 mWh model number: 42T4899 serial number: 21064 battery type: LION OEM info: SANYO Can you see how the values for "design capacity", etc., differ by a factor of 10 instead of 14.8 (the design voltage of this battery)? On the battery itself it says: 14.8V, 1.95Ah, 29Wh, so clearly the values reported in mWh are correct and the ones in mAh are not. My guess is that this problem has been around ever since those machines were released, but because the most common Thinkpad batteries are rated at 10.8V, the error (8%) is small enough that it simply hasn't been noticed or at least nobody could be bothered to look into it. My patch works around the problem by adjusting the incorrectly reported mAh values by "10000 / design_voltage". The patch also has code to figure out if it should be activated or not. It only activates on Lenovo Thinkpads, only when the unit is mAh, and, as an extra precaution, only when the battery capacity reported through ACPI does not match what is reported through DMI (I've never encountered a machine where the first two conditions would be true but the last would not, but better safe than sorry). I've been using this patch for close to a year on several systems without any problems. References: https://bugzilla.kernel.org/show_bug.cgi?id=41062 Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-01-03ACPI: missing breakAlan Cox
commit 879dca019dc43a1622edca3e7dde644b14b5acc5 upstream. We handle NOTIFY_THROTTLING so don't then fall through to unsupported event. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-30ACPI: EC: Add a quirk for CLEVO M720T/M730T laptopFeng Tang
commit 67bfa9b60bd689601554526d144b21d529f78a09 upstream. By enlarging the GPE storm threshold back to 20, that laptop's EC works fine with interrupt mode instead of polling mode. https://bugzilla.kernel.org/show_bug.cgi?id=45151 Reported-and-Tested-by: Francesco <trentini@dei.unipd.it> Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-30ACPI: EC: Make the GPE storm threshold a module parameterFeng Tang
commit a520d52e99b14ba7db135e916348f12f2a6e09be upstream. The Linux EC driver includes a mechanism to detect GPE storms, and switch from interrupt-mode to polling mode. However, polling mode sometimes doesn't work, so the workaround is problematic. Also, different systems seem to need the threshold for detecting the GPE storm at different levels. ACPI_EC_STORM_THRESHOLD was initially 20 when it's created, and was changed to 8 in 2.6.28 commit 06cf7d3c7 "ACPI: EC: lower interrupt storm threshold" to fix kernel bug 11892 by forcing the laptop in that bug to work in polling mode. However in bug 45151, it works fine in interrupt mode if we lift the threshold back to 20. This patch makes the threshold a module parameter so that user has a flexible option to debug/workaround this issue. The default is unchanged. This is also a preparation patch to fix specific systems: https://bugzilla.kernel.org/show_bug.cgi?id=45151 Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-10-17ACPI: run _OSC after ACPI_FULL_INITIALIZATIONLin Ming
commit fc54ab72959edbf229b65ac74b2f122d799ca002 upstream. The _OSC method may exist in module level code, so it must be called after ACPI_FULL_INITIALIZATION On some new platforms with Zero-Power-Optical-Disk-Drive (ZPODD) support, this fix is necessary to save power. Signed-off-by: Lin Ming <ming.m.lin@intel.com> Tested-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-12ACPI: export symbol acpi_get_table_with_sizeAlex Deucher
commit 4f81f986761a7663db7d24d24cd6ae68008f1fc2 upstream. We need it in the radeon drm module to fetch and verify the vbios image on UEFI systems. Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-02ACPI/AC: prevent OOPS on some boxes due to missing check ↵Lan Tianyu
power_supply_register() return value check commit f197ac13f6eeb351b31250b9ab7d0da17434ea36 upstream. In the ac.c, power_supply_register()'s return value is not checked. As a result, the driver's add() ops may return success even though the device failed to initialize. For example, some BIOS may describe two ACADs in the same DSDT. The second ACAD device will fail to register, but ACPI driver's add() ops returns sucessfully. The ACPI device will receive ACPI notification and cause OOPS. https://bugzilla.redhat.com/show_bug.cgi?id=772730 Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-25ACPI / PM: Make acpi_pm_device_sleep_state() follow the specificationRafael J. Wysocki
commit dbe9a2edd17d843d80faf2b99f20a691c1853418 upstream. The comparison between the system sleep state being entered and the lowest system sleep state the given device may wake up from in acpi_pm_device_sleep_state() is reversed, because the specification (ACPI 5.0) says that for wakeup to work: "The sleeping state being entered must be less than or equal to the power state declared in element 1 of the _PRW object." In other words, the state returned by _PRW is the deepest (lowest-power) system sleep state the device is capable of waking up the system from. Moreover, acpi_pm_device_sleep_state() also should check if the wakeup capability is supported through ACPI, because in principle it may be done via native PCIe PME, for example, in which case _SxW should not be evaluated. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-25ACPI sysfs.c strlen fixPavel Vasilyev
commit 9f132652d94c96476b0b0a8caf0c10e96ab10fa8 upstream. Current code is ignoring the last character of "enable" and "disable" in comparisons. https://bugzilla.kernel.org/show_bug.cgi?id=33732 Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-25cpufreq / ACPI: Fix not loading acpi-cpufreq driver regressionThomas Renninger
commit c4686c71a9183f76e3ef59098da5c098748672f6 upstream. Commit d640113fe80e45ebd4a5b420b introduced a regression on SMP systems where the processor core with ACPI id zero is disabled (typically should be the case because of hyperthreading). The regression got spread through stable kernels. On 3.0.X it got introduced via 3.0.18. Such platforms may be rare, but do exist. Look out for a disabled processor with acpi_id 0 in dmesg: ACPI: LAPIC (acpi_id[0x00] lapic_id[0x10] disabled) This problem has been observed on a: HP Proliant BL280c G6 blade This patch restricts the introduced workaround to platforms with nr_cpu_ids <= 1. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-04acpi_pad: fix power_saving thread deadlockStuart Hayes
commit 5f1601261050251a5ca293378b492a69d590dacb upstream. The acpi_pad driver can get stuck in destroy_power_saving_task() waiting for kthread_stop() to stop a power_saving thread. The problem is that the isolated_cpus_lock mutex is owned when destroy_power_saving_task() calls kthread_stop(), which waits for a power_saving thread to end, and the power_saving thread tries to acquire the isolated_cpus_lock when it calls round_robin_cpu(). This patch fixes the issue by making round_robin_cpu() use its own mutex. https://bugzilla.kernel.org/show_bug.cgi?id=42981 Signed-off-by: Stuart Hayes <Stuart_Hayes@Dell.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-06-10ACPI battery: only refresh the sysfs files when pertinent information changesAndy Whitcroft
commit c5971456964290da7e98222892797b71ef793e62 upstream. We only need to regenerate the sysfs files when the capacity units change, avoid the update otherwise. The origin of this issue is dates way back to 2.6.38: da8aeb92d4853f37e281f11fddf61f9c7d84c3cd (ACPI / Battery: Update information on info notification and resume) Signed-off-by: Andy Whitcroft <apw@canonical.com> Tested-by: Ralf Jung <post@ralfj.de> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31ACPI / PM: Add Sony Vaio VPCCW29FX to nonvs blacklist.Lan Tianyu
commit 93f770846e8dedc5d9117bd4ad9d7efd18420627 upstream. Sony Vaio VPCCW29FX does not resume correctly without acpi_sleep=nonvs, so add it to the ACPI sleep blacklist. https://bugzilla.kernel.org/show_bug.cgi?id=34722 Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-04-22ACPICA: Fix to allow region arguments to reference other scopesLin Ming
commit 8931d9ea78848b073bf299594f148b83abde4a5e upstream. Allow referenced objects to be in a different scope. http://www.acpica.org/bugzilla/show_bug.cgi?id=937 http://marc.info/?l=linux-acpi&m=131636632718222&w=2 ACPI Error: [RAMB] Namespace lookup failure, AE_NOT_FOUND (20110112/psargs-359) ACPI Exception: AE_NOT_FOUND, Could not execute arguments for [RAMW] (Region) (20110112/nsinit-349) Scope (_SB) { Name (RAMB, 0xDF5A1018) OperationRegion (\RAMW, SystemMemory, RAMB, 0x00010000) } For above ASL code, we need to save scope node(\_SB) to lookup the argument node(\_SB.RAMB). Reported-by: Jim Green <student.northwestern@gmail.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13ACPICA: Fix regression in FADT revision checksJulian Anastasov
commit 3e80acd1af40fcd91a200b0416a7616b20c5d647 upstream. commit 64b3db22c04586997ab4be46dd5a5b99f8a2d390 (2.6.39), "Remove use of unreliable FADT revision field" causes regression for old P4 systems because now cst_control and other fields are not reset to 0. The effect is that acpi_processor_power_init will notice cst_control != 0 and a write to CST_CNT register is performed that should not happen. As result, the system oopses after the "No _CST, giving up" message, sometimes in acpi_ns_internalize_name, sometimes in acpi_ns_get_type, usually at random places. May be during migration to CPU 1 in acpi_processor_get_throttling. Every one of these settings help to avoid this problem: - acpi=off - processor.nocst=1 - maxcpus=1 The fix is to update acpi_gbl_FADT.header.length after the original value is used to check for old revisions. https://bugzilla.kernel.org/show_bug.cgi?id=42700 https://bugzilla.redhat.com/show_bug.cgi?id=727865 Signed-off-by: Julian Anastasov <ja@ssi.bg> Acked-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Cc: Jonathan Nieder <jrnieder@gmail.com> Cc: Josh Boyer <jwboyer@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13ACPI: Do cpufreq clamping for throttling per package v2Andi Kleen
commit 2815ab92ba3ab27556212cc306288dc95692824b upstream. On Intel CPUs the processor typically uses the highest frequency set by any logical CPU. When the system overheats Linux first forces the frequency to the lowest available one to lower the temperature. However this was done only per logical CPU, which means all logical CPUs in a package would need to go through this before the frequency is actually lowered. Worse this delay actually prevents real throttling, because the real throttle code only proceeds when the lowest frequency is already reached. So when a throttle event happens force the lowest frequency for all CPUs in the package where it happened. The per CPU state is now kept per package, not per logical CPU. An alternative would be to do it per cpufreq unit, but since we want to bring down the temperature of the complete chip it's better to do it for all. In principle it may even make sense to do it for all CPUs, but I kept it on the package for now. With this change the frequency is actually lowered, which in terms also allows real throttling to proceed. I also removed an unnecessary per cpu variable initialization. v2: Fix package mapping Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-12ACPI / PM: Do not save/restore NVS on Asus K54C/K54HRKeng-Yu Lin
commit 5a50a7c32d630d6cdb13d69afabb0cc81b2f379c upstream. The models do not resume correctly without acpi_sleep=nonvs. Signed-off-by: Keng-Yu Lin <kengyu@canonical.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-06PCI: Rework ASPM disable codeMatthew Garrett
commit 3c076351c4027a56d5005a39a0b518a4ba393ce2 upstream. Right now we forcibly clear ASPM state on all devices if the BIOS indicates that the feature isn't supported. Based on the Microsoft presentation "PCI Express In Depth for Windows Vista and Beyond", I'm starting to think that this may be an error. The implication is that unless the platform grants full control via _OSC, Windows will not touch any PCIe features - including ASPM. In that case clearing ASPM state would be an error unless the platform has granted us that control. This patch reworks the ASPM disabling code such that the actual clearing of state is triggered by a successful handoff of PCIe control to the OS. The general ASPM code undergoes some changes in order to ensure that the ability to clear the bits isn't overridden by ASPM having already been disabled. Further, this theoretically now allows for situations where only a subset of PCIe roots hand over control, leaving the others in the BIOS state. It's difficult to know for sure that this is the right thing to do - there's zero public documentation on the interaction between all of these components. But enough vendors enable ASPM on platforms and then set this bit that it seems likely that they're expecting the OS to leave them alone. Measured to save around 5W on an idle Thinkpad X220. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-25ACPI: processor: fix acpi_get_cpuid for UP processorLin Ming
commit d640113fe80e45ebd4a5b420b220d3f6bf37f682 upstream. For UP processor, it is likely that no _MAT method or MADT table defined. So currently acpi_get_cpuid(...) always return -1 for UP processor. This is wrong. It should return valid value for CPU0. In the other hand, BIOS may define multiple CPU handles even for UP processor, for example Scope (_PR) { Processor (CPU0, 0x00, 0x00000410, 0x06) {} Processor (CPU1, 0x01, 0x00000410, 0x06) {} Processor (CPU2, 0x02, 0x00000410, 0x06) {} Processor (CPU3, 0x03, 0x00000410, 0x06) {} } We should only return valid value for CPU0's acpi handle. And return invalid value for others. http://marc.info/?t=132329819900003&r=1&w=2 Reported-and-tested-by: wallak@free.fr Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-25ACPICA: Put back the call to acpi_os_validate_addressLin Ming
commit da4d8b287abe783d30e968155614531a0937d090 upstream. The call to acpi_os_validate_address in acpi_ds_get_region_arguments was removed by mistake in commit 9ad19ac(ACPICA: Split large dsopcode and dsload.c files). Put it back. Reported-and-bisected-by: Luca Tettamanti <kronos.it@gmail.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-25ACPI: Store SRAT table revisionKurt Garloff
commit 8df0eb7c9d96f9e82f233ee8b74e0f0c8471f868 upstream. In SRAT v1, we had 8bit proximity domain (PXM) fields; SRAT v2 provides 32bits for these. The new fields were reserved before. According to the ACPI spec, the OS must disregrard reserved fields. In order to know whether or not, we must know what version the SRAT table has. This patch stores the SRAT table revision for later consumption by arch specific __init functions. Signed-off-by: Kurt Garloff <kurt@garloff.de> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-17pstore: pass allocated memory region back to callerKees Cook
The buf_lock cannot be held while populating the inodes, so make the backend pass forward an allocated and filled buffer instead. This solves the following backtrace. The effect is that "buf" is only ever used to notify the backends that something was written to it, and shouldn't be used in the read path. To replace the buf_lock during the read path, isolate the open/read/close loop with a separate mutex to maintain serialized access to the backend. Note that is is up to the pstore backend to cope if the (*write)() path is called in the middle of the read path. [ 59.691019] BUG: sleeping function called from invalid context at .../mm/slub.c:847 [ 59.691019] in_atomic(): 0, irqs_disabled(): 1, pid: 1819, name: mount [ 59.691019] Pid: 1819, comm: mount Not tainted 3.0.8 #1 [ 59.691019] Call Trace: [ 59.691019] [<810252d5>] __might_sleep+0xc3/0xca [ 59.691019] [<810a26e6>] kmem_cache_alloc+0x32/0xf3 [ 59.691019] [<810b53ac>] ? __d_lookup_rcu+0x6f/0xf4 [ 59.691019] [<810b68b1>] alloc_inode+0x2a/0x64 [ 59.691019] [<810b6903>] new_inode+0x18/0x43 [ 59.691019] [<81142447>] pstore_get_inode.isra.1+0x11/0x98 [ 59.691019] [<81142623>] pstore_mkfile+0xae/0x26f [ 59.691019] [<810a2a66>] ? kmem_cache_free+0x19/0xb1 [ 59.691019] [<8116c821>] ? ida_get_new_above+0x140/0x158 [ 59.691019] [<811708ea>] ? __init_rwsem+0x1e/0x2c [ 59.691019] [<810b67e8>] ? inode_init_always+0x111/0x1b0 [ 59.691019] [<8102127e>] ? should_resched+0xd/0x27 [ 59.691019] [<8137977f>] ? _cond_resched+0xd/0x21 [ 59.691019] [<81142abf>] pstore_get_records+0x52/0xa7 [ 59.691019] [<8114254b>] pstore_fill_super+0x7d/0x91 [ 59.691019] [<810a7ff5>] mount_single+0x46/0x82 [ 59.691019] [<8114231a>] pstore_mount+0x15/0x17 [ 59.691019] [<811424ce>] ? pstore_get_inode.isra.1+0x98/0x98 [ 59.691019] [<810a8199>] mount_fs+0x5a/0x12d [ 59.691019] [<810b9174>] ? alloc_vfsmnt+0xa4/0x14a [ 59.691019] [<810b9474>] vfs_kern_mount+0x4f/0x7d [ 59.691019] [<810b9d7e>] do_kern_mount+0x34/0xb2 [ 59.691019] [<810bb15f>] do_mount+0x5fc/0x64a [ 59.691019] [<810912fb>] ? strndup_user+0x2e/0x3f [ 59.691019] [<810bb3cb>] sys_mount+0x66/0x99 [ 59.691019] [<8137b537>] sysenter_do_call+0x12/0x26 Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2011-11-12ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend regression)Rafael J. Wysocki
After commit e978aa7d7d57 ("cpuidle: Move dev->last_residency update to driver enter routine; remove dev->last_state") setting acpi_idle_suspend to 1 by acpi_processor_suspend() causes the ACPI cpuidle routines to return error codes continuously, which in turn causes cpuidle to lock up (hard). However, acpi_idle_suspend doesn't appear to be useful for any particular purpose (it's racy and doesn't really provide any real protection), so it can be removed, which makes the problem go away. Reported-and-tested-by: Tomas M. <tmezzadra@gmail.com> Reported-and-tested-by: Ferenc Wagner <wferi@niif.hu> Tested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-07Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: cpuidle: Single/Global registration of idle states cpuidle: Split cpuidle_state structure and move per-cpu statistics fields cpuidle: Remove CPUIDLE_FLAG_IGNORE and dev->prepare() cpuidle: Move dev->last_residency update to driver enter routine; remove dev->last_state ACPI: Fix CONFIG_ACPI_DOCK=n compiler warning ACPI: Export FADT pm_profile integer value to userspace thermal: Prevent polling from happening during system suspend ACPI: Drop ACPI_NO_HARDWARE_INIT ACPI atomicio: Convert width in bits to bytes in __acpi_ioremap_fast() PNPACPI: Simplify disabled resource registration ACPI: Fix possible recursive locking in hwregs.c ACPI: use kstrdup() mrst pmu: update comment tools/power turbostat: less verbose debugging
2011-11-06Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
2011-11-06Merge branches 'acpi', 'idle', 'mrst-pmu' and 'pm-tools' into nextLen Brown
2011-11-06Merge branches 'atomic-io', 'lockdep', 'misc', 'pm-profile' and ↵Len Brown
'pnp-cleanup' into acpi
2011-11-06cpuidle: Single/Global registration of idle statesDeepthi Dharwar
This patch makes the cpuidle_states structure global (single copy) instead of per-cpu. The statistics needed on per-cpu basis by the governor are kept per-cpu. This simplifies the cpuidle subsystem as state registration is done by single cpu only. Having single copy of cpuidle_states saves memory. Rare case of asymmetric C-states can be handled within the cpuidle driver and architectures such as POWER do not have asymmetric C-states. Having single/global registration of all the idle states, dynamic C-state transitions on x86 are handled by the boot cpu. Here, the boot cpu would disable all the devices, re-populate the states and later enable all the devices, irrespective of the cpu that would receive the notification first. Reference: https://lkml.org/lkml/2011/4/25/83 Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com> Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com> Tested-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Len Brown <len.brown@intel.com>
2011-11-06cpuidle: Split cpuidle_state structure and move per-cpu statistics fieldsDeepthi Dharwar
This is the first step towards global registration of cpuidle states. The statistics used primarily by the governor are per-cpu and have to be split from rest of the fields inside cpuidle_state, which would be made global i.e. single copy. The driver_data field is also per-cpu and moved. Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com> Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com> Tested-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Len Brown <len.brown@intel.com>
2011-11-06cpuidle: Move dev->last_residency update to driver enter routine; remove ↵Deepthi Dharwar
dev->last_state Cpuidle governor only suggests the state to enter using the governor->select() interface, but allows the low level driver to override the recommended state. The actual entered state may be different because of software or hardware demotion. Software demotion is done by the back-end cpuidle driver and can be accounted correctly. Current cpuidle code uses last_state field to capture the actual state entered and based on that updates the statistics for the state entered. Ideally the driver enter routine should update the counters, and it should return the state actually entered rather than the time spent there. The generic cpuidle code should simply handle where the counters live in the sysfs namespace, not updating the counters. Reference: https://lkml.org/lkml/2011/3/25/52 Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com> Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com> Tested-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Len Brown <len.brown@intel.com>
2011-11-06ACPI: Export FADT pm_profile integer value to userspaceThomas Renninger
There are a lot userspace approaches to detect the usage of the platform (laptop, workstation, server, ...) and adjust kernel tunables accordingly (io/process scheduler, power management, ...). These approaches need constant maintaining and are ugly to implement (detect PCMCIA controller -> laptop, does not work on recent systems anymore, ...) On ACPI systems there is an easy and reliable way (if implemented in BIOS and most recent platforms have this value set). -> export it to userspace. Signed-off-by: Thomas Renninger <trenn@suse.de> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>