[alsa-devel] [PATCH v4 4/6] ASoC: fsl_ssi: Fix samples being dropped at Playback startup

[Caleb Crome]

On Tue, May 3, 2016 at 5:24 AM, Fabio Estevam <festevam at gmail.com> wrote:
> On Tue, May 3, 2016 at 9:13 AM, Arnaud Mouiche
> <arnaud.mouiche at 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 at invoxia.com>
>
> Reviewed-by: Fabio Estevam <fabio.estevam at nxp.com>
Tested-by: Caleb Crome <caleb at crome.org>