From 9dd926d29051324d8621ca2a18bbdd568523ac93 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Sat, 14 Sep 2019 17:24:05 +0200 Subject: [PATCH] staging: bcm2835-audio: Fix draining behavior regression 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 --- 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_192000, .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_44100 | SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 | --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c @@ -297,6 +297,7 @@ 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 = {