diff options
| author | Daniel Mack <zonque@gmail.com> | 2012-08-29 13:17:05 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2012-08-30 07:46:27 +0200 |
| commit | 015618b902ae8e28705b7af9b4668615fea48ddd (patch) | |
| tree | 43832c8eeaad08cf294da8a438512815858cfa66 /sound/usb/endpoint.c | |
| parent | c36b5b054aaf14d68261970e3769398110e636d8 (diff) | |
ALSA: snd-usb: Fix URB cancellation at stream start
Commit e9ba389c5 ("ALSA: usb-audio: Fix scheduling-while-atomic bug in
PCM capture stream") fixed a scheduling-while-atomic bug that happened
when snd_usb_endpoint_start was called from the trigger callback, which
is an atmic context. However, the patch breaks the idea of the endpoints
reference counting, which is the reason why the driver has been
refactored lately.
Revert that commit and let snd_usb_endpoint_start() take care of the URB
cancellation again. As this function is called from both atomic and
non-atomic context, add a flag to denote whether the function may sleep.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: stable@kernel.org [3.5+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/endpoint.c')
| -rw-r--r-- | sound/usb/endpoint.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index c41181202688..b896c5559524 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -799,7 +799,9 @@ int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep, /** * snd_usb_endpoint_start: start an snd_usb_endpoint * - * @ep: the endpoint to start + * @ep: the endpoint to start + * @can_sleep: flag indicating whether the operation is executed in + * non-atomic context * * A call to this function will increment the use count of the endpoint. * In case it is not already running, the URBs for this endpoint will be @@ -809,7 +811,7 @@ int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep, * * Returns an error if the URB submission failed, 0 in all other cases. */ -int snd_usb_endpoint_start(struct snd_usb_endpoint *ep) +int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, int can_sleep) { int err; unsigned int i; @@ -821,6 +823,11 @@ int snd_usb_endpoint_start(struct snd_usb_endpoint *ep) if (++ep->use_count != 1) return 0; + /* just to be sure */ + deactivate_urbs(ep, 0, can_sleep); + if (can_sleep) + wait_clear_urbs(ep); + ep->active_mask = 0; ep->unlink_mask = 0; ep->phase = 0; |