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path: root/drivers/usb/storage/usb.c
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Diffstat (limited to 'drivers/usb/storage/usb.c')
-rw-r--r--drivers/usb/storage/usb.c77
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)