Commit 52869931 authored Nov 13, 2019 by Henry Lin Committed by Takashi Iwai Nov 13, 2019

ALSA: usb-audio: not submit urb for stopped endpoint



While output urb's snd_complete_urb() is executing, calling
prepare_outbound_urb() may cause endpoint stopped before
prepare_outbound_urb() returns and result in next urb submitted
to stopped endpoint. usb-audio driver cannot re-use it afterwards as
the urb is still hold by usb stack.

This change checks EP_FLAG_RUNNING flag after prepare_outbound_urb() again
to let snd_complete_urb() know the endpoint already stopped and does not
submit next urb. Below kind of error will be fixed:

[  213.153103] usb 1-2: timeout: still 1 active urbs on EP #1
[  213.164121] usb 1-2: cannot submit urb 0, error -16: unknown error

Signed-off-by: Henry Lin <henryl@nvidia.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191113021420.13377-1-henryl@nvidia.com


Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent a7d0358e

sound/usb/endpoint.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -388,6 +388,9 @@ static void snd_complete_urb(struct urb *urb)
		}

		prepare_outbound_urb(ep, ctx);
		/* can be stopped during prepare callback */
		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
		goto exit_clear;
		} else {
		retire_inbound_urb(ep, ctx);
		/* can be stopped during retire callback */

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