From: Takashi Iwai tiwai@suse.de
commit 2eed19b99c8e95ff87afe6c140ed895c3fac5937 upstream.
The PCM draining behavior got broken since the recent refactoring, and this turned out to be the incorrect expectation of the firmware behavior regarding "draining". While I expected the "drain" flag at the stop operation would do processing the queued samples, it seems rather dropping the samples.
As a quick fix, just drop the SNDRV_PCM_INFO_DRAIN_TRIGGER flag, so that the driver uses the normal PCM draining procedure. Also, put some caution comment to the function for future readers not to fall into the same pitfall.
Fixes: d7ca3a71545b ("staging: bcm2835-audio: Operate non-atomic PCM ops") BugLink: https://github.com/raspberrypi/linux/issues/2983 Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai tiwai@suse.de Acked-by: Stefan Wahren wahrenst@gmx.net Link: https://lore.kernel.org/r/20190914152405.7416-1-tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c | 4 ++-- drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c | 1 + 2 files changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c @@ -12,7 +12,7 @@ static const struct snd_pcm_hardware snd_bcm2835_playback_hw = { .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | - SNDRV_PCM_INFO_DRAIN_TRIGGER | SNDRV_PCM_INFO_SYNC_APPLPTR), + SNDRV_PCM_INFO_SYNC_APPLPTR), .formats = SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE, .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000, .rate_min = 8000, @@ -29,7 +29,7 @@ static const struct snd_pcm_hardware snd static const struct snd_pcm_hardware snd_bcm2835_playback_spdif_hw = { .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | - SNDRV_PCM_INFO_DRAIN_TRIGGER | SNDRV_PCM_INFO_SYNC_APPLPTR), + SNDRV_PCM_INFO_SYNC_APPLPTR), .formats = SNDRV_PCM_FMTBIT_S16_LE, .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000, --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c @@ -289,6 +289,7 @@ int bcm2835_audio_stop(struct bcm2835_al VC_AUDIO_MSG_TYPE_STOP, false); }
+/* FIXME: this doesn't seem working as expected for "draining" */ int bcm2835_audio_drain(struct bcm2835_alsa_stream *alsa_stream) { struct vc_audio_msg m = {