Commit 0ef74366 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: usb-audio: Add spinlock to stop_urbs() 

In theory, stop_urbs() may be called concurrently.
Although we have the state check beforehand, it's safer to apply
ep->lock during the critical list head manipulations.

Link: https://lore.kernel.org/r/20210929080844.11583-8-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent d215f63d

sound/usb/endpoint.c

+3 −0
Original line number Diff line number Diff line
@@ -927,6 +927,7 @@ void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep) 
static int stop_urbs(struct snd_usb_endpoint *ep, bool force)

{

	unsigned int i;

	unsigned long flags;



	if (!force && atomic_read(&ep->running))

		return -EBUSY;
@@ -934,9 +935,11 @@ static int stop_urbs(struct snd_usb_endpoint *ep, bool force) 
	if (!ep_state_update(ep, EP_STATE_RUNNING, EP_STATE_STOPPING))

		return 0;



	spin_lock_irqsave(&ep->lock, flags);

	INIT_LIST_HEAD(&ep->ready_playback_urbs);

	ep->next_packet_head = 0;

	ep->next_packet_queued = 0;

	spin_unlock_irqrestore(&ep->lock, flags);



	for (i = 0; i < ep->nurbs; i++) {

		if (test_bit(i, &ep->active_mask)) {