[alsa-devel] [PATCH] ASoC: Intel: cht_bsw_rt5645: Add quirk for boards using pmc_plt_clk_0

[Pierre-Louis Bossart]

On 9/16/19 2:15 AM, Sam McNally wrote:
> As of commit 648e921888ad ("clk: x86: Stop marking clocks as
> CLK_IS_CRITICAL"), the cht_bsw_rt5645 driver needs to enable the clock
> it's using for the codec's mclk. It does this from commit 7735bce05a9c
> ("ASoC: Intel: boards: use devm_clk_get() unconditionally"), enabling
> pmc_plt_clk_3. However, Strago family Chromebooks use pmc_plt_clk_0 for
> the codec mclk, resulting in white noise with some digital microphones.
> Add a DMI-based quirk for Strago family Chromebooks to use pmc_plt_clk_0
> instead.

Sounds good, thanks for the patch. You will need to Cc: maintainers 
(Takashi and Mark) if you want them to see your patches.

Maybe you should mention in the commit message that this mirrors the 
changes made in cht_bsw_max98090_ti?

Also see more important comment below

> 
> Signed-off-by: Sam McNally <sammc at chromium.org>
> ---
> 
>   sound/soc/intel/boards/cht_bsw_rt5645.c | 26 +++++++++++++++++++------
>   1 file changed, 20 insertions(+), 6 deletions(-)
> 
> diff --git a/sound/soc/intel/boards/cht_bsw_rt5645.c b/sound/soc/intel/boards/cht_bsw_rt5645.c
> index 8879c3be29d5..c68a5b85a4a0 100644
> --- a/sound/soc/intel/boards/cht_bsw_rt5645.c
> +++ b/sound/soc/intel/boards/cht_bsw_rt5645.c
> @@ -48,6 +48,7 @@ struct cht_mc_private {
>   #define CHT_RT5645_SSP2_AIF2     BIT(16) /* default is using AIF1  */
>   #define CHT_RT5645_SSP0_AIF1     BIT(17)
>   #define CHT_RT5645_SSP0_AIF2     BIT(18)
> +#define CHT_RT5645_PMC_PLT_CLK_0 BIT(19)
>   
>   static unsigned long cht_rt5645_quirk = 0;
>   
> @@ -59,6 +60,8 @@ static void log_quirks(struct device *dev)
>   		dev_info(dev, "quirk SSP0_AIF1 enabled");
>   	if (cht_rt5645_quirk & CHT_RT5645_SSP0_AIF2)
>   		dev_info(dev, "quirk SSP0_AIF2 enabled");
> +	if (cht_rt5645_quirk & CHT_RT5645_PMC_PLT_CLK_0)
> +		dev_info(dev, "quirk PMC_PLT_CLK_0 enabled");
>   }
>   
>   static int platform_clock_control(struct snd_soc_dapm_widget *w,
> @@ -226,15 +229,21 @@ static int cht_aif1_hw_params(struct snd_pcm_substream *substream,
>   	return 0;
>   }
>   
> -/* uncomment when we have a real quirk
>   static int cht_rt5645_quirk_cb(const struct dmi_system_id *id)
>   {
>   	cht_rt5645_quirk = (unsigned long)id->driver_data;
>   	return 1;
>   }
> -*/
>   
>   static const struct dmi_system_id cht_rt5645_quirk_table[] = {
> +	{
> +		/* Strago family Chromebooks */
> +		.callback = cht_rt5645_quirk_cb,
> +		.matches = {
> +			DMI_MATCH(DMI_PRODUCT_FAMILY, "Intel_Strago"),
> +		},
> +		.driver_data = (void *)CHT_RT5645_PMC_PLT_CLK_0,
> +	},
>   	{
>   	},
>   };
> @@ -526,6 +535,7 @@ static int snd_cht_mc_probe(struct platform_device *pdev)
>   	int dai_index = 0;
>   	int ret_val = 0;
>   	int i;
> +	const char *mclk_name;
>   
>   	drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
>   	if (!drv)
> @@ -662,11 +672,15 @@ static int snd_cht_mc_probe(struct platform_device *pdev)
>   	if (ret_val)
>   		return ret_val;
>   
> -	drv->mclk = devm_clk_get(&pdev->dev, "pmc_plt_clk_3");
> +	if (cht_rt5645_quirk & CHT_RT5645_PMC_PLT_CLK_0)
> +		mclk_name = "pmc_plt_clk_0";
> +	else
> +		mclk_name = "pmc_plt_clk_3";

Aren't you missing a call to dmi_first_match() to change the default 
value of this cht_rt5645_quirk variable?

The rest of the patch looks good but I don't see how the DMI info is 
actually used.

> +	drv->mclk = devm_clk_get(&pdev->dev, mclk_name);
>   	if (IS_ERR(drv->mclk)) {
> -		dev_err(&pdev->dev,
> -			"Failed to get MCLK from pmc_plt_clk_3: %ld\n",
> -			PTR_ERR(drv->mclk));
> +		dev_err(&pdev->dev, "Failed to get MCLK from %s: %ld\n",
> +			mclk_name, PTR_ERR(drv->mclk)); >   		return PTR_ERR(drv->mclk);
>   	}
>   
>