[PATCH 6.12 350/567] ASoC: qcom: q6apm-dai: set flags to reflect correct operation of appl_ptr

Greg Kroah-Hartman
2026-01-06T17:34:33Z

From: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>

commit 950a4e5788fc7dc6e8e93614a7d4d0449c39fb8d upstream.

Driver does not expect the appl_ptr to move backward and requires
explict sync. Make sure that the userspace does not do appl_ptr rewinds
by specifying the correct flags in pcm_info.

Without this patch, the result could be a forever loop as current logic assumes
that appl_ptr can only move forward.

Fixes: 3d4a4411aa8b ("ASoC: q6apm-dai: schedule all available frames to avoid dsp under-runs")
Cc: Stable@vger.kernel.org
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
Tested-by: Alexey Klimov <alexey.klimov@linaro.org> # RB5, RB3
Link: https://patch.msgid.link/20251023102444.88158-2-srinivas.kandagatla@oss.qualcomm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
sound/soc/qcom/qdsp6/q6apm-dai.c | 2 ++
1 file changed, 2 insertions(+)

--- a/sound/soc/qcom/qdsp6/q6apm-dai.c
+++ b/sound/soc/qcom/qdsp6/q6apm-dai.c
@@ -85,6 +85,7 @@ static const struct snd_pcm_hardware q6a
.info = (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME |
+ SNDRV_PCM_INFO_NO_REWINDS | SNDRV_PCM_INFO_SYNC_APPLPTR |
SNDRV_PCM_INFO_BATCH),
.formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE),
.rates = SNDRV_PCM_RATE_8000_48000,
@@ -104,6 +105,7 @@ static const struct snd_pcm_hardware q6a
.info = (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME |
+ SNDRV_PCM_INFO_NO_REWINDS | SNDRV_PCM_INFO_SYNC_APPLPTR |
SNDRV_PCM_INFO_BATCH),
.formats = (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE),
.rates = SNDRV_PCM_RATE_8000_192000,