* [PATCH] ASoC: fsl_sai: sw reset consumer on pause/stop
@ 2023-09-21 8:48 Emil Abildgaard Svendsen
2023-09-21 14:00 ` Fabio Estevam
0 siblings, 1 reply; 2+ messages in thread
From: Emil Abildgaard Svendsen @ 2023-09-21 8:48 UTC (permalink / raw)
To: Shengjiu Wang, Xiubo Li, Fabio Estevam, Nicolin Chen,
Liam Girdwood, Mark Brown, Jaroslav Kysela, Takashi Iwai,
Matus Gajdos
Cc: alsa-devel@alsa-project.org, linuxppc-dev@lists.ozlabs.org,
Emil Abildgaard Svendsen
When in consumer mode with BCLK disabled (FSL_SAI_CSR_BCE = 0) the
FIFO's can still contain data when resumed. It might also be possible
with BCLK enabled but just less likely.
When the FIFO's still contain data on resume it can cause channel
shifting on e.g. XRUNS. A Software Reset will reset the FIFO's and make
sure channels are aligned.
Fixes: 269f399dc19f ("ASoC: fsl_sai: Disable bit clock with transmitter")
Signed-off-by: Emil Svendsen <emas@bang-olufsen.dk>
---
sound/soc/fsl/fsl_sai.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 1e4020fae05a..1da5c17cd329 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -730,13 +730,18 @@ static void fsl_sai_config_disable(struct fsl_sai *sai, int dir)
* anymore. Add software reset to fix this issue.
* This is a hardware bug, and will be fix in the
* next sai version.
+ *
+ * When in consumer mode with BCLK disabled
+ * (FSL_SAI_CSR_BCE = 0) the FIFO's can still contain
+ * data when resumed. This can cause channel shifting
+ * on e.g. XRUNS. A Software Reset will reset the
+ * FIFO's and make sure the channels aren't shifted.
*/
- if (!sai->is_consumer_mode) {
- /* Software Reset */
- regmap_write(sai->regmap, FSL_SAI_xCSR(tx, ofs), FSL_SAI_CSR_SR);
- /* Clear SR bit to finish the reset */
- regmap_write(sai->regmap, FSL_SAI_xCSR(tx, ofs), 0);
- }
+
+ /* Software Reset */
+ regmap_write(sai->regmap, FSL_SAI_xCSR(tx, ofs), FSL_SAI_CSR_SR);
+ /* Clear SR bit to finish the reset */
+ regmap_write(sai->regmap, FSL_SAI_xCSR(tx, ofs), 0);
}
static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd,
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] ASoC: fsl_sai: sw reset consumer on pause/stop
2023-09-21 8:48 [PATCH] ASoC: fsl_sai: sw reset consumer on pause/stop Emil Abildgaard Svendsen
@ 2023-09-21 14:00 ` Fabio Estevam
0 siblings, 0 replies; 2+ messages in thread
From: Fabio Estevam @ 2023-09-21 14:00 UTC (permalink / raw)
To: Emil Abildgaard Svendsen
Cc: alsa-devel@alsa-project.org, Xiubo Li,
linuxppc-dev@lists.ozlabs.org, Takashi Iwai, Liam Girdwood,
Jaroslav Kysela, Nicolin Chen, Mark Brown, Matus Gajdos,
Shengjiu Wang
On Thu, Sep 21, 2023 at 5:48 AM Emil Abildgaard Svendsen
<EMAS@bang-olufsen.dk> wrote:
>
> When in consumer mode with BCLK disabled (FSL_SAI_CSR_BCE = 0) the
> FIFO's can still contain data when resumed. It might also be possible
> with BCLK enabled but just less likely.
>
> When the FIFO's still contain data on resume it can cause channel
> shifting on e.g. XRUNS. A Software Reset will reset the FIFO's and make
> sure channels are aligned.
>
> Fixes: 269f399dc19f ("ASoC: fsl_sai: Disable bit clock with transmitter")
> Signed-off-by: Emil Svendsen <emas@bang-olufsen.dk>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2023-09-21 8:48 [PATCH] ASoC: fsl_sai: sw reset consumer on pause/stop Emil Abildgaard Svendsen
2023-09-21 14:00 ` Fabio Estevam
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