diff options
Diffstat (limited to 'drivers/usb/storage/usb.c')
| -rw-r--r-- | drivers/usb/storage/usb.c | 77 |
1 files changed, 36 insertions, 41 deletions
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index 6b14f8d253f1..6bfd99dd57aa 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -320,16 +320,17 @@ static int usb_stor_control_thread(void * __us) /* lock the device pointers */ mutex_lock(&(us->dev_mutex)); - /* if the device has disconnected, we are free to exit */ - if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) { - US_DEBUGP("-- exiting\n"); + /* lock access to the state */ + scsi_lock(host); + + /* When we are called with no command pending, we're done */ + if (us->srb == NULL) { + scsi_unlock(host); mutex_unlock(&us->dev_mutex); + US_DEBUGP("-- exiting\n"); break; } - /* lock access to the state */ - scsi_lock(host); - /* has the command timed out *already* ? */ if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) { us->srb->result = DID_ABORT << 16; @@ -384,12 +385,8 @@ static int usb_stor_control_thread(void * __us) /* lock access to the state */ scsi_lock(host); - /* did the command already complete because of a disconnect? */ - if (!us->srb) - ; /* nothing to do */ - /* indicate that the command is done */ - else if (us->srb->result != DID_ABORT << 16) { + if (us->srb->result != DID_ABORT << 16) { US_DEBUGP("scsi cmd done, result=0x%x\n", us->srb->result); us->srb->scsi_done(us->srb); @@ -820,11 +817,10 @@ static void usb_stor_release_resources(struct us_data *us) US_DEBUGP("-- %s\n", __func__); /* Tell the control thread to exit. The SCSI host must - * already have been removed so it won't try to queue - * any more commands. + * already have been removed and the DISCONNECTING flag set + * so that we won't accept any more commands. */ US_DEBUGP("-- sending exit command to thread\n"); - set_bit(US_FLIDX_DISCONNECTING, &us->dflags); complete(&us->cmnd_ready); if (us->ctl_thread) kthread_stop(us->ctl_thread); @@ -859,39 +855,36 @@ static void dissociate_dev(struct us_data *us) usb_set_intfdata(us->pusb_intf, NULL); } -/* First stage of disconnect processing: stop all commands and remove - * the host */ +/* First stage of disconnect processing: stop SCSI scanning, + * remove the host, and stop accepting new commands + */ static void quiesce_and_remove_host(struct us_data *us) { struct Scsi_Host *host = us_to_host(us); - /* Prevent new USB transfers, stop the current command, and - * interrupt a SCSI-scan or device-reset delay */ - scsi_lock(host); - set_bit(US_FLIDX_DISCONNECTING, &us->dflags); - scsi_unlock(host); - usb_stor_stop_transport(us); - wake_up(&us->delay_wait); + /* If the device is really gone, cut short reset delays */ + if (us->pusb_dev->state == USB_STATE_NOTATTACHED) + set_bit(US_FLIDX_DISCONNECTING, &us->dflags); - /* queuecommand won't accept any new commands and the control - * thread won't execute a previously-queued command. If there - * is such a command pending, complete it with an error. */ - mutex_lock(&us->dev_mutex); - if (us->srb) { - us->srb->result = DID_NO_CONNECT << 16; - scsi_lock(host); - us->srb->scsi_done(us->srb); - us->srb = NULL; - complete(&us->notify); /* in case of an abort */ - scsi_unlock(host); - } - mutex_unlock(&us->dev_mutex); + /* Prevent SCSI-scanning (if it hasn't started yet) + * and wait for the SCSI-scanning thread to stop. + */ + set_bit(US_FLIDX_DONT_SCAN, &us->dflags); + wake_up(&us->delay_wait); + wait_for_completion(&us->scanning_done); - /* Now we own no commands so it's safe to remove the SCSI host */ + /* Removing the host will perform an orderly shutdown: caches + * synchronized, disks spun down, etc. + */ scsi_remove_host(host); - /* Wait for the SCSI-scanning thread to stop */ - wait_for_completion(&us->scanning_done); + /* Prevent any new commands from being accepted and cut short + * reset delays. + */ + scsi_lock(host); + set_bit(US_FLIDX_DISCONNECTING, &us->dflags); + scsi_unlock(host); + wake_up(&us->delay_wait); } /* Second stage of disconnect processing: deallocate all resources */ @@ -919,12 +912,12 @@ static int usb_stor_scan_thread(void * __us) printk(KERN_DEBUG "usb-storage: waiting for device " "to settle before scanning\n"); wait_event_freezable_timeout(us->delay_wait, - test_bit(US_FLIDX_DISCONNECTING, &us->dflags), + test_bit(US_FLIDX_DONT_SCAN, &us->dflags), delay_use * HZ); } /* If the device is still connected, perform the scanning */ - if (!test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) { + if (!test_bit(US_FLIDX_DONT_SCAN, &us->dflags)) { /* For bulk-only devices, determine the max LUN value */ if (us->protocol == US_PR_BULK && @@ -1023,6 +1016,7 @@ static int storage_probe(struct usb_interface *intf, if (IS_ERR(th)) { printk(KERN_WARNING USB_STORAGE "Unable to start the device-scanning thread\n"); + complete(&us->scanning_done); quiesce_and_remove_host(us); result = PTR_ERR(th); goto BadDevice; @@ -1065,6 +1059,7 @@ static struct usb_driver usb_storage_driver = { .pre_reset = storage_pre_reset, .post_reset = storage_post_reset, .id_table = storage_usb_ids, + .soft_unbind = 1, }; static int __init usb_stor_init(void) |