[7/8] ASoC: fsl_spdif: fix struct clk pointer comparing

On 02/25/15 06:53, Shawn Guo wrote:
> Since commit 035a61c314eb ("clk: Make clk API return per-user struct clk
> instances"), clk API users can no longer check if two struct clk
> pointers are pointing to the same hardware clock, i.e. struct clk_hw, by
> simply comparing two pointers.  That's because with the per-user clk
> change, a brand new struct clk is created whenever clients try to look
> up the clock by calling clk_get() or sister functions like clk_get_sys()
> and of_clk_get().  This changes the original behavior where the struct
> clk is only created for once when clock driver registers the clock to
> CCF in the first place.  The net change here is before commit
> 035a61c314eb the struct clk pointer is unique for given hardware
> clock, while after the commit the pointers returned by clk lookup calls
> become different for the same hardware clock.
>
> That said, the struct clk pointer comparing in the code doesn't work any
> more.  Call helper function clk_is_match() instead to fix the problem.
>
> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> ---
>  sound/soc/fsl/fsl_spdif.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/sound/soc/fsl/fsl_spdif.c b/sound/soc/fsl/fsl_spdif.c
> index 75870c0ea2c9..91eb3aef7f02 100644
> --- a/sound/soc/fsl/fsl_spdif.c
> +++ b/sound/soc/fsl/fsl_spdif.c
> @@ -1049,7 +1049,7 @@ static u32 fsl_spdif_txclk_caldiv(struct fsl_spdif_priv *spdif_priv,
>  				enum spdif_txrate index, bool round)
>  {
>  	const u32 rate[] = { 32000, 44100, 48000, 96000, 192000 };
> -	bool is_sysclk = clk == spdif_priv->sysclk;
> +	bool is_sysclk = clk_is_match(clk, spdif_priv->sysclk);
>  	u64 rate_ideal, rate_actual, sub;
>  	u32 sysclk_dfmin, sysclk_dfmax;
>  	u32 txclk_df, sysclk_df, arate;
> @@ -1143,7 +1143,7 @@ static int fsl_spdif_probe_txclk(struct fsl_spdif_priv *spdif_priv,
>  			spdif_priv->txclk_src[index], rate[index]);
>  	dev_dbg(&pdev->dev, "use txclk df %d for %dHz sample rate\n",
>  			spdif_priv->txclk_df[index], rate[index]);
> -	if (spdif_priv->txclk[index] == spdif_priv->sysclk)
> +	if (clk_is_match(spdif_priv->txclk[index], spdif_priv->sysclk))
>  		dev_dbg(&pdev->dev, "use sysclk df %d for %dHz sample rate\n",
>  				spdif_priv->sysclk_df[index], rate[index]);
>  	dev_dbg(&pdev->dev, "the best rate for %dHz sample rate is %dHz\n",

Couldn't this be fixed like this?

----8<----

On Wed, Feb 25, 2015 at 01:04:41PM -0800, Stephen Boyd wrote:
> > diff --git a/sound/soc/fsl/fsl_spdif.c b/sound/soc/fsl/fsl_spdif.c
> > index 75870c0ea2c9..91eb3aef7f02 100644
> > --- a/sound/soc/fsl/fsl_spdif.c
> > +++ b/sound/soc/fsl/fsl_spdif.c
> > @@ -1049,7 +1049,7 @@ static u32 fsl_spdif_txclk_caldiv(struct fsl_spdif_priv *spdif_priv,
> >  				enum spdif_txrate index, bool round)
> >  {
> >  	const u32 rate[] = { 32000, 44100, 48000, 96000, 192000 };
> > -	bool is_sysclk = clk == spdif_priv->sysclk;
> > +	bool is_sysclk = clk_is_match(clk, spdif_priv->sysclk);
> >  	u64 rate_ideal, rate_actual, sub;
> >  	u32 sysclk_dfmin, sysclk_dfmax;
> >  	u32 txclk_df, sysclk_df, arate;
> > @@ -1143,7 +1143,7 @@ static int fsl_spdif_probe_txclk(struct fsl_spdif_priv *spdif_priv,
> >  			spdif_priv->txclk_src[index], rate[index]);
> >  	dev_dbg(&pdev->dev, "use txclk df %d for %dHz sample rate\n",
> >  			spdif_priv->txclk_df[index], rate[index]);
> > -	if (spdif_priv->txclk[index] == spdif_priv->sysclk)
> > +	if (clk_is_match(spdif_priv->txclk[index], spdif_priv->sysclk))
> >  		dev_dbg(&pdev->dev, "use sysclk df %d for %dHz sample rate\n",
> >  				spdif_priv->sysclk_df[index], rate[index]);
> >  	dev_dbg(&pdev->dev, "the best rate for %dHz sample rate is %dHz\n",
> 
> Couldn't this be fixed like this?

It could.  But this fix is less-intuitive and makes the code change
unnecessarily complex, considering we are introducing helper
clk_is_match() anyway.

Shawn

> 
> ----8<----
> 
> diff --git a/sound/soc/fsl/fsl_spdif.c b/sound/soc/fsl/fsl_spdif.c
> index af0429421fc8..1878dd62a247 100644
> --- a/sound/soc/fsl/fsl_spdif.c
> +++ b/sound/soc/fsl/fsl_spdif.c
> @@ -20,6 +20,7 @@
>  #include <linux/of_device.h>
>  #include <linux/of_irq.h>
>  #include <linux/regmap.h>
> +#include <linux/stringify.h>
>  
>  #include <sound/asoundef.h>
>  #include <sound/dmaengine_pcm.h>
> @@ -46,6 +47,8 @@ static u8 srpc_dpll_locked[] = { 0x0, 0x1, 0x2, 0x3, 0x4, 0xa, 0xb };
>  
>  #define DEFAULT_RXCLK_SRC	1
>  
> +#define SYSCLK_NUM		5
> +
>  /*
>   * SPDIF control structure
>   * Defines channel status, subcode and Q sub
> @@ -1051,10 +1054,10 @@ static const struct regmap_config fsl_spdif_regmap_config = {
>  
>  static u32 fsl_spdif_txclk_caldiv(struct fsl_spdif_priv *spdif_priv,
>  				struct clk *clk, u64 savesub,
> -				enum spdif_txrate index, bool round)
> +				enum spdif_txrate index, bool round,
> +				bool is_sysclk)
>  {
>  	const u32 rate[] = { 32000, 44100, 48000, 96000, 192000 };
> -	bool is_sysclk = clk == spdif_priv->sysclk;
>  	u64 rate_ideal, rate_actual, sub;
>  	u32 sysclk_dfmin, sysclk_dfmax;
>  	u32 txclk_df, sysclk_df, arate;
> @@ -1131,7 +1134,8 @@ static int fsl_spdif_probe_txclk(struct fsl_spdif_priv *spdif_priv,
>  			continue;
>  
>  		ret = fsl_spdif_txclk_caldiv(spdif_priv, clk, savesub, index,
> -					     i == STC_TXCLK_SPDIF_ROOT);
> +					     i == STC_TXCLK_SPDIF_ROOT,
> +					     i == SYSCLK_NUM);
>  		if (savesub == ret)
>  			continue;
>  
> @@ -1210,7 +1214,8 @@ static int fsl_spdif_probe(struct platform_device *pdev)
>  	}
>  
>  	/* Get system clock for rx clock rate calculation */
> -	spdif_priv->sysclk = devm_clk_get(&pdev->dev, "rxtx5");
> +	spdif_priv->sysclk = devm_clk_get(&pdev->dev,
> +					  "rxtx" __stringify(SYSCLK_NUM));
>  	if (IS_ERR(spdif_priv->sysclk)) {
>  		dev_err(&pdev->dev, "no sys clock (rxtx5) in devicetree\n");
>  		return PTR_ERR(spdif_priv->sysclk);
> 
> 
> -- 
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 
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