[PATCH V2] opp: Don't ignore clk_get() errors other than -ENOENT

[PATCH V2] opp: Don't ignore clk_get() errors other than -ENOENT

[Viresh Kumar]

Not all devices that need to use OPP core need to have clocks, a missing
clock is fine in which case -ENOENT shall be returned by clk_get().

Anything else is an error and must be handled properly.

Reported-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
V2:
- s/ENODEV/ENOENT
- Use dev_err_probe()

Stephen, is the understanding correct that -ENOENT is the only error
returned for missing clocks ?

 drivers/opp/core.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index a518173fd64a..0beb3ee79523 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1252,6 +1252,8 @@ static struct opp_table *_update_opp_table_clk(struct device *dev,
 					       struct opp_table *opp_table,
 					       bool getclk)
 {
+	int ret;
+
 	/*
 	 * Return early if we don't need to get clk or we have already tried it
 	 * earlier.
@@ -1261,18 +1263,19 @@ static struct opp_table *_update_opp_table_clk(struct device *dev,
 
 	/* Find clk for the device */
 	opp_table->clk = clk_get(dev, NULL);
-	if (IS_ERR(opp_table->clk)) {
-		int ret = PTR_ERR(opp_table->clk);
 
-		if (ret == -EPROBE_DEFER) {
-			dev_pm_opp_put_opp_table(opp_table);
-			return ERR_PTR(ret);
-		}
+	ret = PTR_ERR_OR_ZERO(opp_table->clk);
+	if (!ret)
+		return opp_table;
 
+	if (ret == -ENOENT) {
 		dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__, ret);
+		return opp_table;
 	}
 
-	return opp_table;
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return ERR_PTR(dev_err_probe(dev, ret, "Couldn't find clock\n"));
 }
 
 /*
-- 
2.25.0.rc1.19.g042ed3e048af

Re: [PATCH V2] opp: Don't ignore clk_get() errors other than -ENOENT

[Dmitry Osipenko]

01.02.2021 07:22, Viresh Kumar пишет:
> Not all devices that need to use OPP core need to have clocks, a missing
> clock is fine in which case -ENOENT shall be returned by clk_get().
> 
> Anything else is an error and must be handled properly.
> 
> Reported-by: Dmitry Osipenko <digetx@gmail.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> V2:
> - s/ENODEV/ENOENT
> - Use dev_err_probe()
> 
> Stephen, is the understanding correct that -ENOENT is the only error
> returned for missing clocks ?
> 
>  drivers/opp/core.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index a518173fd64a..0beb3ee79523 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -1252,6 +1252,8 @@ static struct opp_table *_update_opp_table_clk(struct device *dev,
>  					       struct opp_table *opp_table,
>  					       bool getclk)
>  {
> +	int ret;
> +
>  	/*
>  	 * Return early if we don't need to get clk or we have already tried it
>  	 * earlier.
> @@ -1261,18 +1263,19 @@ static struct opp_table *_update_opp_table_clk(struct device *dev,
>  
>  	/* Find clk for the device */
>  	opp_table->clk = clk_get(dev, NULL);
> -	if (IS_ERR(opp_table->clk)) {
> -		int ret = PTR_ERR(opp_table->clk);
>  
> -		if (ret == -EPROBE_DEFER) {
> -			dev_pm_opp_put_opp_table(opp_table);
> -			return ERR_PTR(ret);
> -		}
> +	ret = PTR_ERR_OR_ZERO(opp_table->clk);
> +	if (!ret)
> +		return opp_table;
>  
> +	if (ret == -ENOENT) {
>  		dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__, ret);
> +		return opp_table;
>  	}
>  
> -	return opp_table;
> +	dev_pm_opp_put_opp_table(opp_table);
> +
> +	return ERR_PTR(dev_err_probe(dev, ret, "Couldn't find clock\n"));
>  }
>  
>  /*
> 

Thanks, looks okay.

Although, I think the previous variant of coding style was a bit more appropriate, i.e. like this:

dev_err_probe(dev, "%s: Couldn't find clock: %d\n", __func__, ret);

return ERR_PTR(ret);

Re: [PATCH V2] opp: Don't ignore clk_get() errors other than -ENOENT

[Viresh Kumar]

On 01-02-21, 22:54, Dmitry Osipenko wrote:
> Thanks, looks okay.
> 
> Although, I think the previous variant of coding style was a bit more appropriate, i.e. like this:
> 
> dev_err_probe(dev, "%s: Couldn't find clock: %d\n", __func__, ret);
> 
> return ERR_PTR(ret);

Okay will move to that.

-- 
viresh

Re: [PATCH V2] opp: Don't ignore clk_get() errors other than -ENOENT

[Stephen Boyd]

Quoting Viresh Kumar (2021-01-31 20:22:58)
> Not all devices that need to use OPP core need to have clocks, a missing
> clock is fine in which case -ENOENT shall be returned by clk_get().
> 
> Anything else is an error and must be handled properly.
> 
> Reported-by: Dmitry Osipenko <digetx@gmail.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> V2:
> - s/ENODEV/ENOENT
> - Use dev_err_probe()
> 
> Stephen, is the understanding correct that -ENOENT is the only error
> returned for missing clocks ?

Yeah pretty much. See clk_get_optional().