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@xxxxxxxxxx>
> ---
> 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);
> }
