Re: [PATCH] ASoC: Intel: kbl_rt5663_max98927: Simplify clk_get() usage

On 8/7/22 22:18, Christophe JAILLET wrote:

If clk_get() returns -ENOENT, there is no need to defer the driver, -ENOENT will be returned the same for each retries. So, return the error code directly instead of -EPROBE_DEFER.

Remove this special case and use dev_err_probe() to simplify code. It will also be less verbose if the clk is really deferred.

Fixes: f7f61e08fe58 ("ASoC: Intel: kbl: Enable mclk and ssp sclk early") Signed-off-by: Christophe JAILLET christophe.jaillet@wanadoo.fr

---

This is based on my understanding of clk_get(). Review with care.

Not sure the Fixes tag is needed. The patch does not fix anything. If devm_clk_get() returns -ENOENT, it will just loop several time until the framework gives up. If it returns -EPROBE_DEFER, this case is already handled by the "return ret;"

So this patch should be a no-op, just a clean-up.

I can't pretend understanding the clk framework in depth, but the only case where -ENOENT is returned seems to be this block in clk_hw_create_clk()

if (!try_module_get(core->owner)) { free_clk(clk); return ERR_PTR(-ENOENT); }

I have no idea why this would be converted to a -EPROBE_DEFER. May to account for module loading?

---

sound/soc/intel/boards/kbl_rt5663_max98927.c | 31 ++++---------------- 1 file changed, 6 insertions(+), 25 deletions(-)

diff --git a/sound/soc/intel/boards/kbl_rt5663_max98927.c b/sound/soc/intel/boards/kbl_rt5663_max98927.c index 2d4224c5b152..07b00af2fa3c 100644 --- a/sound/soc/intel/boards/kbl_rt5663_max98927.c +++ b/sound/soc/intel/boards/kbl_rt5663_max98927.c @@ -989,7 +989,6 @@ static int kabylake_audio_probe(struct platform_device *pdev) { struct kbl_rt5663_private *ctx; struct snd_soc_acpi_mach *mach;

• int ret;

  ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); if (!ctx)

@@ -1009,32 +1008,14 @@ static int kabylake_audio_probe(struct platform_device *pdev) &constraints_dmic_2ch : &constraints_dmic_channels;

ctx->mclk = devm_clk_get(&pdev->dev, "ssp1_mclk");

• if (IS_ERR(ctx->mclk)) {

• ret = PTR_ERR(ctx->mclk);
  

• if (ret == -ENOENT) {
  

• 	dev_info(&pdev->dev,
  

• 		"Failed to get ssp1_sclk, defer probe\n");
  

• 	return -EPROBE_DEFER;
  

• }
  

• dev_err(&pdev->dev, "Failed to get ssp1_mclk with err:%d\n",
  

• 						ret);
  

• return ret;
  

• }

• if (IS_ERR(ctx->mclk))

• return dev_err_probe(&pdev->dev, PTR_ERR(ctx->mclk),
  

• 		     "Failed to get ssp1_mclk\n");
  
  

  ctx->sclk = devm_clk_get(&pdev->dev, "ssp1_sclk");

• if (IS_ERR(ctx->sclk)) {

• ret = PTR_ERR(ctx->sclk);
  

• if (ret == -ENOENT) {
  

• 	dev_info(&pdev->dev,
  

• 		"Failed to get ssp1_sclk, defer probe\n");
  

• 	return -EPROBE_DEFER;
  

• }
  

• dev_err(&pdev->dev, "Failed to get ssp1_sclk with err:%d\n",
  

• 						ret);
  

• return ret;
  

• }

• if (IS_ERR(ctx->sclk))

• return dev_err_probe(&pdev->dev, PTR_ERR(ctx->sclk),
  

• 		     "Failed to get ssp1_sclk\n");
  
  

  return devm_snd_soc_register_card(&pdev->dev, kabylake_audio_card);

}