ASoC: fsl_ssi: Fix samples being dropped at Playback startup
authorArnaud Mouiche <arnaud.mouiche@invoxia.com>
Tue, 3 May 2016 12:13:58 +0000 (14:13 +0200)
committerMark Brown <broonie@kernel.org>
Fri, 13 May 2016 11:15:31 +0000 (12:15 +0100)
commitd9f2a202877c15818d98268f47d6b4bcfcb84437
tree19910d1343b8c3f56e89fd2a5b72d3ca48cac430
parent0096b693962d3abde4f41b13cf03c765f33e9d8d
ASoC: fsl_ssi: Fix samples being dropped at Playback startup

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>
Signed-off-by: Mark Brown <broonie@kernel.org>
sound/soc/fsl/fsl_ssi.c