diff options
Diffstat (limited to 'drivers/usb/storage/uas.c')
-rw-r--r-- | drivers/usb/storage/uas.c | 79 |
1 files changed, 75 insertions, 4 deletions
diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index 0d044d59317e..de4d33fbf6b8 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -45,6 +45,7 @@ struct uas_dev_info { struct scsi_cmnd *cmnd[MAX_CMNDS]; spinlock_t lock; struct work_struct work; + struct work_struct scan_work; /* for async scanning */ }; enum { @@ -80,6 +81,19 @@ static void uas_free_streams(struct uas_dev_info *devinfo); static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix, int status); +/* + * This driver needs its own workqueue, as we need to control memory allocation. + * + * In the course of error handling and power management uas_wait_for_pending_cmnds() + * needs to flush pending work items. In these contexts we cannot allocate memory + * by doing block IO as we would deadlock. For the same reason we cannot wait + * for anything allocating memory not heeding these constraints. + * + * So we have to control all work items that can be on the workqueue we flush. + * Hence we cannot share a queue and need our own. + */ +static struct workqueue_struct *workqueue; + static void uas_do_work(struct work_struct *work) { struct uas_dev_info *devinfo = @@ -108,12 +122,23 @@ static void uas_do_work(struct work_struct *work) if (!err) cmdinfo->state &= ~IS_IN_WORK_LIST; else - schedule_work(&devinfo->work); + queue_work(workqueue, &devinfo->work); } out: spin_unlock_irqrestore(&devinfo->lock, flags); } +static void uas_scan_work(struct work_struct *work) +{ + struct uas_dev_info *devinfo = + container_of(work, struct uas_dev_info, scan_work); + struct Scsi_Host *shost = usb_get_intfdata(devinfo->intf); + + dev_dbg(&devinfo->intf->dev, "starting scan\n"); + scsi_scan_host(shost); + dev_dbg(&devinfo->intf->dev, "scan complete\n"); +} + static void uas_add_work(struct uas_cmd_info *cmdinfo) { struct scsi_pointer *scp = (void *)cmdinfo; @@ -122,7 +147,7 @@ static void uas_add_work(struct uas_cmd_info *cmdinfo) lockdep_assert_held(&devinfo->lock); cmdinfo->state |= IS_IN_WORK_LIST; - schedule_work(&devinfo->work); + queue_work(workqueue, &devinfo->work); } static void uas_zap_pending(struct uas_dev_info *devinfo, int result) @@ -178,6 +203,9 @@ static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix, struct uas_cmd_info *ci = (void *)&cmnd->SCp; struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp; + if (status == -ENODEV) /* too late */ + return; + scmd_printk(KERN_INFO, cmnd, "%s %d uas-tag %d inflight:%s%s%s%s%s%s%s%s%s%s%s%s ", prefix, status, cmdinfo->uas_tag, @@ -825,6 +853,10 @@ static int uas_slave_configure(struct scsi_device *sdev) sdev->wce_default_on = 1; } + /* Some disks cannot handle READ_CAPACITY_16 */ + if (devinfo->flags & US_FL_NO_READ_CAPACITY_16) + sdev->no_read_capacity_16 = 1; + /* * Some disks return the total number of blocks in response * to READ CAPACITY rather than the highest block number. @@ -834,6 +866,12 @@ static int uas_slave_configure(struct scsi_device *sdev) sdev->fix_capacity = 1; /* + * in some cases we have to guess + */ + if (devinfo->flags & US_FL_CAPACITY_HEURISTICS) + sdev->guess_capacity = 1; + + /* * Some devices don't like MODE SENSE with page=0x3f, * which is the command used for checking if a device * is write-protected. Now that we tell the sd driver @@ -973,6 +1011,7 @@ static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id) init_usb_anchor(&devinfo->data_urbs); spin_lock_init(&devinfo->lock); INIT_WORK(&devinfo->work, uas_do_work); + INIT_WORK(&devinfo->scan_work, uas_scan_work); result = uas_configure_endpoints(devinfo); if (result) @@ -989,7 +1028,9 @@ static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id) if (result) goto free_streams; - scsi_scan_host(shost); + /* Submit the delayed_work for SCSI-device scanning */ + schedule_work(&devinfo->scan_work); + return result; free_streams: @@ -1157,6 +1198,12 @@ static void uas_disconnect(struct usb_interface *intf) usb_kill_anchored_urbs(&devinfo->data_urbs); uas_zap_pending(devinfo, DID_NO_CONNECT); + /* + * Prevent SCSI scanning (if it hasn't started yet) + * or wait for the SCSI-scanning routine to stop. + */ + cancel_work_sync(&devinfo->scan_work); + scsi_remove_host(shost); uas_free_streams(devinfo); scsi_host_put(shost); @@ -1196,7 +1243,31 @@ static struct usb_driver uas_driver = { .id_table = uas_usb_ids, }; -module_usb_driver(uas_driver); +static int __init uas_init(void) +{ + int rv; + + workqueue = alloc_workqueue("uas", WQ_MEM_RECLAIM, 0); + if (!workqueue) + return -ENOMEM; + + rv = usb_register(&uas_driver); + if (rv) { + destroy_workqueue(workqueue); + return -ENOMEM; + } + + return 0; +} + +static void __exit uas_exit(void) +{ + usb_deregister(&uas_driver); + destroy_workqueue(workqueue); +} + +module_init(uas_init); +module_exit(uas_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR( |