[alsa-devel] [PATCH] ASoC: Intel: bytcr_rt5640: fallback mechanism if MCLK is not enabled

[Takashi Iwai]

On Tue, 13 Dec 2016 19:41:30 +0100,
Pierre-Louis Bossart wrote:
> 
> Commit df1a2776a795 ("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.
> 
> This patch should be applied to -stable as well as ASoC 4.10 fixes
> 
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>

Reviewed-by: Takashi Iwai <tiwai at suse.de>
Cc: <stable at vger.kernel.org> # v4.9
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=117141


Takashi

> ---
>  sound/soc/intel/boards/bytcr_rt5640.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/soc/intel/boards/bytcr_rt5640.c b/sound/soc/intel/boards/bytcr_rt5640.c
> index 507a86a..4a8b509 100644
> --- a/sound/soc/intel/boards/bytcr_rt5640.c
> +++ b/sound/soc/intel/boards/bytcr_rt5640.c
> @@ -828,7 +828,9 @@ static int snd_byt_rt5640_mc_probe(struct platform_device *pdev)
>  			dev_err(&pdev->dev,
>  				"Failed to get MCLK from pmc_plt_clk_3: %ld\n",
>  				PTR_ERR(priv->mclk));
> -			return PTR_ERR(priv->mclk);
> +
> +			/* Fall back to bitclock only */
> +			byt_rt5640_quirk &= ~BYT_RT5640_MCLK_EN;
>  		}
>  	}
>  
> -- 
> 2.9.3
>