Unverified Commit c656941d authored Apr 08, 2018 by Nicolin Chen Committed by Mark Brown Apr 12, 2018

ASoC: fsl_esai: Fix divisor calculation failure at lower ratio



When the desired ratio is less than 256, the savesub (tolerance)
in the calculation would become 0. This will then fail the loop-
search immediately without reporting any errors.

But if the ratio is smaller enough, there is no need to calculate
the tolerance because PM divisor alone is enough to get the ratio.

So a simple fix could be just to set PM directly instead of going
into the loop-search.

Reported-by: Marek Vasut <marex@denx.de>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Marek Vasut <marex@denx.de>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

parent 573eda59

sound/soc/fsl/fsl_esai.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -144,6 +144,13 @@ static int fsl_esai_divisor_cal(struct snd_soc_dai *dai, bool tx, u32 ratio,

		psr = ratio <= 256 * maxfp ? ESAI_xCCR_xPSR_BYPASS : ESAI_xCCR_xPSR_DIV8;

		/* Do not loop-search if PM (1 ~ 256) alone can serve the ratio */
		if (ratio <= 256) {
		pm = ratio;
		fp = 1;
		goto out;
		}

		/* Set the max fluctuation -- 0.1% of the max devisor */
		savesub = (psr ? 1 : 8) * 256 * maxfp / 1000;