| Message ID | 1462277640-20052-5-git-send-email-arnaud.mouiche@invoxia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 3, 2016 at 9:13 AM, Arnaud Mouiche <arnaud.mouiche@invoxia.com> wrote: > If the capture is already running while playback is started, it is highly > probable (>80% in a 8 channels scenario) that samples are lost between > the DMA and TX fifo. > > The reason is that SIER.TDMAE is set before STCR.TFEN0, leaving a time > window where the FIFO doesn't receive the samples written by the DMA. > > This particular case happened only if capture is already enabled as > SCR.SSIEN is already set at the playback startup instant. > > Signed-off-by: Arnaud Mouiche <arnaud.mouiche@invoxia.com> Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
On Tue, May 3, 2016 at 5:24 AM, Fabio Estevam <festevam@gmail.com> wrote: > On Tue, May 3, 2016 at 9:13 AM, Arnaud Mouiche > <arnaud.mouiche@invoxia.com> wrote: >> If the capture is already running while playback is started, it is highly >> probable (>80% in a 8 channels scenario) that samples are lost between >> the DMA and TX fifo. >> >> The reason is that SIER.TDMAE is set before STCR.TFEN0, leaving a time >> window where the FIFO doesn't receive the samples written by the DMA. >> >> This particular case happened only if capture is already enabled as >> SCR.SSIEN is already set at the playback startup instant. >> >> Signed-off-by: Arnaud Mouiche <arnaud.mouiche@invoxia.com> > > Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com> Tested-by: Caleb Crome <caleb@crome.org>
diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c index 695f041..3917741 100644 --- a/sound/soc/fsl/fsl_ssi.c +++ b/sound/soc/fsl/fsl_ssi.c @@ -476,9 +476,9 @@ static void fsl_ssi_config(struct fsl_ssi_private *ssi_private, bool enable, * (online configuration) */ if (enable) { - regmap_update_bits(regs, CCSR_SSI_SIER, vals->sier, vals->sier); regmap_update_bits(regs, CCSR_SSI_SRCR, vals->srcr, vals->srcr); regmap_update_bits(regs, CCSR_SSI_STCR, vals->stcr, vals->stcr); + regmap_update_bits(regs, CCSR_SSI_SIER, vals->sier, vals->sier); } else { u32 sier; u32 srcr;
If the capture is already running while playback is started, it is highly probable (>80% in a 8 channels scenario) that samples are lost between the DMA and TX fifo. The reason is that SIER.TDMAE is set before STCR.TFEN0, leaving a time window where the FIFO doesn't receive the samples written by the DMA. This particular case happened only if capture is already enabled as SCR.SSIEN is already set at the playback startup instant. Signed-off-by: Arnaud Mouiche <arnaud.mouiche@invoxia.com> --- sound/soc/fsl/fsl_ssi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)