Re: [PATCH 3/3] ASoC: rsnd: add null CLOCKIN support

Hi Geert

I'm not such a big fan of creating dummy clocks.
And what if a future SoC lacks two CLOCKIN pins? Then you'll try to
register a second dummy clock with the same name, which will fail,
presumably?

I think current code will reuse same null_clk for these.

This should only be done when the clock does not exist, not in case
of other errors (e.g. -EPROBE_DEFER, which isn't handled yet)?

As devm_clk_get_optional() already checks for existence, you could use:

    struct clk *clk = devm_clk_get_optional(dev, clk_name[i]);
    if (!clk)
            clk = rsnd_adg_null_clk_get(priv);

Ah, indeed.
Thanks. I will fix it.

But in light of the above (avoiding dummy clocks), it might be more
robust to make sure all code can handle adg->clk[i] = NULL?

The reason why I don't use adg->clk[i] = NULL is it is using this macro

	#define for_each_rsnd_clk(pos, adg, i)		\
		for (i = 0;				\
		     (i < CLKMAX) &&			\
		     ((pos) = adg->clk[i]);		\
		     i++)

The loop will stop at (A) if it was

	adg->clk[0] = audio_clk_a;
	adg->clk[1] = audio_clk_b;
(A)	adg->clk[2] = NULL
	adg->clk[3] = audio_clk_i;

Thank you for your help !!

Best regards
---
Kuninori Morimoto