diff options
| author | Daniel Girnus <dgirnus@de.adit-jv.com> | 2016-12-06 14:46:15 +0900 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2016-12-06 13:55:15 +0100 |
| commit | 1e2e3fe480064ca33186e5a923beaa160efed35d (patch) | |
| tree | ab3155a9ffd5391a54b5072a798615e71d382b54 /sound/usb | |
| parent | 4763601a56f155ddf94ef35fc2c41504a2de15f5 (diff) | |
| download | linux-1e2e3fe480064ca33186e5a923beaa160efed35d.tar.bz2 | |
ALSA: usb-audio: avoid setting of sample rate multiple times on bus
Some of userland applications call 'snd_pcm_hw_params()' and
'snd_pcm_hw_prepare()' sequentially, which means 'snd_pcm_hw_prepare()'
is called twice and the second 'snd_pcm_hw_prepare()' is called in
'SNDRV_PCM_STATE_PREPARED' state.
Some devices are not able to manage this and they will stop playback
if the sample rate will be configured several times over USB protocol.
V2: updated Changelog
Signed-off-by: Daniel Girnus <dgirnus@de.adit-jv.com>
Signed-off-by: Jens Lorenz <jlorenz@de.adit-jv.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb')
| -rw-r--r-- | sound/usb/pcm.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 44d178ee9177..a522c9af1f34 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -806,17 +806,18 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream) if (ret < 0) goto unlock; - iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface); - alts = &iface->altsetting[subs->cur_audiofmt->altset_idx]; - ret = snd_usb_init_sample_rate(subs->stream->chip, - subs->cur_audiofmt->iface, - alts, - subs->cur_audiofmt, - subs->cur_rate); - if (ret < 0) - goto unlock; - if (subs->need_setup_ep) { + + iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface); + alts = &iface->altsetting[subs->cur_audiofmt->altset_idx]; + ret = snd_usb_init_sample_rate(subs->stream->chip, + subs->cur_audiofmt->iface, + alts, + subs->cur_audiofmt, + subs->cur_rate); + if (ret < 0) + goto unlock; + ret = configure_endpoint(subs); if (ret < 0) goto unlock; |