Commit 4a8b3a68 authored Dec 16, 2016 by Pierre-Louis Bossart Committed by Mark Brown Dec 19, 2016

ASoC: Intel: bytcr_rt5640: fallback mechanism if MCLK is not enabled

Commit df1a2776 ("ASoC: Intel: bytcr_rt5640: add MCLK support")
was merged but the corresponding clock framework patches have not,
after being bumped from audio to clock to x86 domains. The missing
clock-related patches result in a regression starting with 4.9 with
the audio card not being created.

Rather than reverting this commit and all following updates already
queued up for 4.10, handle run-time dependency on MCLK and fall back
to the previous bit-clock mode. This provides the same functionality
as in 4.8 for Baytrail devices. On Baytrail-CR most devices remain
silent with this fallback but additional patches are needed anyway.
As suggested by Mark Brown, the fallback is only allowed with -ENOENT,
all other run-time errors, including -EPROBE_DEFER, will stop the probe
with no sound card registered.

This patch should be applied to -stable as well as ASoC 4.10 fixes

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent a5de5b74

sound/soc/intel/boards/bytcr_rt5640.c

+13 −3

Original line number	Diff line number	Diff line
		@@ -825,10 +825,20 @@ static int snd_byt_rt5640_mc_probe(struct platform_device *pdev)
		if ((byt_rt5640_quirk & BYT_RT5640_MCLK_EN) && (is_valleyview())) {
		priv->mclk = devm_clk_get(&pdev->dev, "pmc_plt_clk_3");
		if (IS_ERR(priv->mclk)) {
		ret_val = PTR_ERR(priv->mclk);

		dev_err(&pdev->dev,
		"Failed to get MCLK from pmc_plt_clk_3: %ld\n",
		PTR_ERR(priv->mclk));
		return PTR_ERR(priv->mclk);
		"Failed to get MCLK from pmc_plt_clk_3: %d\n",
		ret_val);

		/*
		* Fall back to bit clock usage for -ENOENT (clock not
		* available likely due to missing dependencies), bail
		* for all other errors, including -EPROBE_DEFER
		*/
		if (ret_val != -ENOENT)
		return ret_val;
		byt_rt5640_quirk &= ~BYT_RT5640_MCLK_EN;
		}
		}