Eric Lee / smarc-ti-linux-kernel

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Commit c6fdd8e5d0c65bb8821dc6da26ee1a2ddd58b3cc

Authored by Tilman Schmidt
Committed by David S. Miller
1 parent 910a578f7e
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

bas_gigaset: fix pre_reset handling 

The delayed work function int_in_work() may call usb_reset_device()
and thus, indirectly, the driver's pre_reset method. Trying to
cancel the work synchronously in that situation would deadlock.
Fix by avoiding cancel_work_sync() in the pre_reset method.

If the reset was NOT initiated by int_in_work() this might cause
int_in_work() to run after the post_reset method, with urb_int_in
already resubmitted, so handle that case gracefully.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

Showing 1 changed file with 16 additions and 3 deletions Side-by-side Diff

drivers/isdn/gigaset/bas-gigaset.c
Diff comments   View file @ c6fdd8e
... ... @@ -617,7 +617,13 @@
617 617 if (rc == 0)
618 618 /* success, resubmit interrupt read URB */
619 619 rc = usb_submit_urb(urb, GFP_ATOMIC);
620   - if (rc != 0 && rc != -ENODEV) {
  620 +
  621 + switch (rc) {
  622 + case 0: /* success */
  623 + case -ENODEV: /* device gone */
  624 + case -EINVAL: /* URB already resubmitted, or terminal badness */
  625 + break;
  626 + default: /* failure: try to recover by resetting the device */
621 627 dev_err(cs->dev, "clear halt failed: %s\n", get_usb_rcmsg(rc));
622 628 rc = usb_lock_device_for_reset(ucs->udev, ucs->interface);
623 629 if (rc == 0) {
... ... @@ -2442,7 +2448,9 @@
2442 2448 }
2443 2449  
2444 2450 /* gigaset_suspend
2445   - * This function is called before the USB connection is suspended.
  2451 + * This function is called before the USB connection is suspended
  2452 + * or before the USB device is reset.
  2453 + * In the latter case, message == PMSG_ON.
2446 2454 */
2447 2455 static int gigaset_suspend(struct usb_interface *intf, pm_message_t message)
2448 2456 {
... ... @@ -2498,7 +2506,12 @@
2498 2506 del_timer_sync(&ucs->timer_atrdy);
2499 2507 del_timer_sync(&ucs->timer_cmd_in);
2500 2508 del_timer_sync(&ucs->timer_int_in);
2501   - cancel_work_sync(&ucs->int_in_wq);
  2509 +
  2510 + /* don't try to cancel int_in_wq from within reset as it
  2511 + * might be the one requesting the reset
  2512 + */
  2513 + if (message.event != PM_EVENT_ON)
  2514 + cancel_work_sync(&ucs->int_in_wq);
2502 2515  
2503 2516 gig_dbg(DEBUG_SUSPEND, "suspend complete");
2504 2517 return 0;