Commit c2e1d907 authored Jul 20, 2012 by Dong Aisheng Committed by Mark Brown Jul 24, 2012

ASoC: mxs-saif: fix clock prepare and enable unbalance issue



Currently we directly call a clock_enable in trigger function without
a clk_prepare as pair first.
This will cause system hang immediately when run capture because
the clock was not prepared(playback does not hang because the clock was
prepared already by get_mclk before), a warning message in clock framework
may cause a deadlock to reclaim clock lock (see: pl011_console_write).

Here we prepare clock first in hw_param, then enable it in trigger
function to guarantee the balance.

Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

parent b8edf3e5

sound/soc/mxs/mxs-saif.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -394,9 +394,14 @@ static int mxs_saif_hw_params(struct snd_pcm_substream *substream,
		struct snd_soc_dai *cpu_dai)
		{
		struct mxs_saif *saif = snd_soc_dai_get_drvdata(cpu_dai);
		struct mxs_saif *master_saif;
		u32 scr, stat;
		int ret;

		master_saif = mxs_saif_get_master(saif);
		if (!master_saif)
		return -EINVAL;

		/* mclk should already be set */
		if (!saif->mclk && saif->mclk_in_use) {
		dev_err(cpu_dai->dev, "set mclk first\n");
		@@ -420,6 +425,11 @@ static int mxs_saif_hw_params(struct snd_pcm_substream *substream,
		return ret;
		}

		/* prepare clk in hw_param, enable in trigger */
		clk_prepare(saif->clk);
		if (saif != master_saif)
		clk_prepare(master_saif->clk);

		scr = __raw_readl(saif->base + SAIF_CTRL);

		scr &= ~BM_SAIF_CTRL_WORD_LENGTH;