6.6-stable review patch. If anyone has any objections, please let me know.
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From: Sheetal sheetal@nvidia.com
[ Upstream commit 9aff2e8df240e84a36f2607f98a0a9924a24e65d ]
Issue: When multiple audio streams share a common BE DAI, the BE DAI widget can be powered up before its hardware parameters are configured. This incorrect sequence leads to intermittent pcm_write errors.
For example, the below Tegra use-case throws an error: aplay(2 streams) -> AMX(mux) -> ADX(demux) -> arecord(2 streams), here, 'AMX TX' and 'ADX RX' are common BE DAIs.
For above usecase when failure happens below sequence is observed: aplay(1) FE open() - BE DAI callbacks added to the list - BE DAI state = SND_SOC_DPCM_STATE_OPEN aplay(2) FE open() - BE DAI callbacks are not added to the list as the state is already SND_SOC_DPCM_STATE_OPEN during aplay(1) FE open(). aplay(2) FE hw_params() - BE DAI hw_params() callback ignored aplay(2) FE prepare() - Widget is powered ON without BE DAI hw_params() call aplay(1) FE hw_params() - BE DAI hw_params() is now called
Fix: Add BE DAIs in the list if its state is either SND_SOC_DPCM_STATE_OPEN or SND_SOC_DPCM_STATE_HW_PARAMS as well.
It ensures the widget is powered ON after BE DAI hw_params() callback.
Fixes: 0c25db3f7621 ("ASoC: soc-pcm: Don't reconnect an already active BE") Signed-off-by: Sheetal sheetal@nvidia.com Link: https://patch.msgid.link/20250404105953.2784819-1-sheetal@nvidia.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- sound/soc/soc-pcm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 60248a6820aac..30e93f9aad762 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -1534,10 +1534,13 @@ static int dpcm_add_paths(struct snd_soc_pcm_runtime *fe, int stream, /* * Filter for systems with 'component_chaining' enabled. * This helps to avoid unnecessary re-configuration of an - * already active BE on such systems. + * already active BE on such systems and ensures the BE DAI + * widget is powered ON after hw_params() BE DAI callback. */ if (fe->card->component_chaining && (be->dpcm[stream].state != SND_SOC_DPCM_STATE_NEW) && + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN) && + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) && (be->dpcm[stream].state != SND_SOC_DPCM_STATE_CLOSE)) continue;