diff options
| author | Takashi Iwai <tiwai@suse.de> | 2012-09-06 14:58:00 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2012-09-06 15:00:15 +0200 |
| commit | 1213a205f9ed27d97de3d5bed28fb085ef4853e2 (patch) | |
| tree | d29a9631b965cd0bf788d475f6fc563e240b48ed /sound/usb | |
| parent | ab548d2dba63ba947287965e525cc02a15d9853d (diff) | |
| download | linux-1213a205f9ed27d97de3d5bed28fb085ef4853e2.tar.bz2 | |
ALSA: usb-audio: Fix bogus error messages for delay accounting
The recent fix for the missing fine delayed time adjustment gives
strange error messages at each start of the playback stream, such as
delay: estimated 0, actual 352
delay: estimated 353, actual 705
These come from the sanity check in retire_playback_urb(). Before the
stream is activated via start_endpoints(), a few silent packets have
been already sent. And at this point the delay account is still in
the state as if the new packets are just queued, so the driver gets
confused and spews the bogus error messages.
For fixing the issue, we just need to check whether the received
packet is valid, whether it's zero sized or not.
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: <stable@vger.kernel.org> [v3.5+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb')
| -rw-r--r-- | sound/usb/pcm.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index fd5e982fc98c..f782ce19bf5a 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -1140,6 +1140,12 @@ static void retire_playback_urb(struct snd_usb_substream *subs, int processed = urb->transfer_buffer_length / stride; int est_delay; + /* ignore the delay accounting when procssed=0 is given, i.e. + * silent payloads are procssed before handling the actual data + */ + if (!processed) + return; + spin_lock_irqsave(&subs->lock, flags); est_delay = snd_usb_pcm_delay(subs, runtime->rate); /* update delay with exact number of samples played */ |