[PATCH] ASoC: fsl: fsl_qmc_audio: Reset audio data pointers on TRIGGER_START event

[Christophe Leroy]

Le 10/04/2025 à 11:16, Herve Codina a écrit :
> On SNDRV_PCM_TRIGGER_START event, audio data pointers are not reset.
> 
> This leads to wrong data buffer usage when multiple TRIGGER_START are
> received and ends to incorrect buffer usage between the user-space and
> the driver. Indeed, the driver can read data that are not already set by
> the user-space or the user-space and the driver are writing and reading
> the same area.
> 
> Fix that resetting data pointers on each SNDRV_PCM_TRIGGER_START events.
> 
> Fixes: 075c7125b11c ("ASoC: fsl: Add support for QMC audio")
> Cc: stable at vger.kernel.org
> Signed-off-by: Herve Codina <herve.codina at bootlin.com>


Reviewed-by: Christophe Leroy <christophe.leroy at csgroup.eu>


Tested-by: Christophe Leroy <christophe.leroy at csgroup.eu>



> ---
>   sound/soc/fsl/fsl_qmc_audio.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/sound/soc/fsl/fsl_qmc_audio.c b/sound/soc/fsl/fsl_qmc_audio.c
> index b2979290c973..5614a8b909ed 100644
> --- a/sound/soc/fsl/fsl_qmc_audio.c
> +++ b/sound/soc/fsl/fsl_qmc_audio.c
> @@ -250,6 +250,9 @@ static int qmc_audio_pcm_trigger(struct snd_soc_component *component,
>   	switch (cmd) {
>   	case SNDRV_PCM_TRIGGER_START:
>   		bitmap_zero(prtd->chans_pending, 64);
> +		prtd->buffer_ended = 0;
> +		prtd->ch_dma_addr_current = prtd->ch_dma_addr_start;
> +
>   		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
>   			for (i = 0; i < prtd->channels; i++)
>   				prtd->qmc_dai->chans[i].prtd_tx = prtd;