[PATCH v2] hwrng: meson - Improve error handling for core clock

[PATCH v2] hwrng: meson - Improve error handling for core clock

[Uwe Kleine-König]

-ENOENT (ie. "there is no clock") is fine to ignore for an optional
clock, other values are not supposed to be ignored and should be
escalated to the caller (e.g. -EPROBE_DEFER). Ignore -ENOENT by using
devm_clk_get_optional().

While touching this code also add an error message for the fatal errors.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
Hello,

compared to (implicit) v1
(https://lore.kernel.org/r/20210914142428.57099-1-u.kleine-koenig@pengutronix.de)
this used dev_err_probe() as suggested by Martin Blumenstingl.

v1 got a "Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>", I didn't add
that because of the above change.

(Hmm, my setup is broken, the b4 patch signature was done before I added this
message. I wonder if this will break the signature ...)

Best regards
Uwe

 drivers/char/hw_random/meson-rng.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
index e446236e81f2..8bb30282ca46 100644
--- a/drivers/char/hw_random/meson-rng.c
+++ b/drivers/char/hw_random/meson-rng.c
@@ -54,9 +54,10 @@ static int meson_rng_probe(struct platform_device *pdev)
 	if (IS_ERR(data->base))
 		return PTR_ERR(data->base);
 
-	data->core_clk = devm_clk_get(dev, "core");
+	data->core_clk = devm_clk_get_optional(dev, "core");
 	if (IS_ERR(data->core_clk))
-		data->core_clk = NULL;
+		return dev_err_probe(dev, PTR_ERR(data->core_clk),
+				     "Failed to get core clock\n");
 
 	if (data->core_clk) {
 		ret = clk_prepare_enable(data->core_clk);

base-commit: 7d2a07b769330c34b4deabeed939325c77a7ec2f
-- 
2.30.2

Re: [PATCH v2] hwrng: meson - Improve error handling for core clock

[Neil Armstrong]

On 20/09/2021 09:44, Uwe Kleine-König wrote:
> -ENOENT (ie. "there is no clock") is fine to ignore for an optional
> clock, other values are not supposed to be ignored and should be
> escalated to the caller (e.g. -EPROBE_DEFER). Ignore -ENOENT by using
> devm_clk_get_optional().
> 
> While touching this code also add an error message for the fatal errors.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
> Hello,
> 
> compared to (implicit) v1
> (https://lore.kernel.org/r/20210914142428.57099-1-u.kleine-koenig@pengutronix.de)
> this used dev_err_probe() as suggested by Martin Blumenstingl.
> 
> v1 got a "Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>", I didn't add
> that because of the above change.
> 

Hopefully martin did a better review than me !

Anyway,
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>

Neil

> (Hmm, my setup is broken, the b4 patch signature was done before I added this
> message. I wonder if this will break the signature ...)
> 
> Best regards
> Uwe
> 
>  drivers/char/hw_random/meson-rng.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
> index e446236e81f2..8bb30282ca46 100644
> --- a/drivers/char/hw_random/meson-rng.c
> +++ b/drivers/char/hw_random/meson-rng.c
> @@ -54,9 +54,10 @@ static int meson_rng_probe(struct platform_device *pdev)
>  	if (IS_ERR(data->base))
>  		return PTR_ERR(data->base);
>  
> -	data->core_clk = devm_clk_get(dev, "core");
> +	data->core_clk = devm_clk_get_optional(dev, "core");
>  	if (IS_ERR(data->core_clk))
> -		data->core_clk = NULL;
> +		return dev_err_probe(dev, PTR_ERR(data->core_clk),
> +				     "Failed to get core clock\n");
>  
>  	if (data->core_clk) {
>  		ret = clk_prepare_enable(data->core_clk);
> 
> base-commit: 7d2a07b769330c34b4deabeed939325c77a7ec2f
> 

Re: [PATCH v2] hwrng: meson - Improve error handling for core clock

[Martin Blumenstingl]

On Mon, Sep 20, 2021 at 9:44 AM Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> wrote:
>
> -ENOENT (ie. "there is no clock") is fine to ignore for an optional
> clock, other values are not supposed to be ignored and should be
> escalated to the caller (e.g. -EPROBE_DEFER). Ignore -ENOENT by using
> devm_clk_get_optional().
>
> While touching this code also add an error message for the fatal errors.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
as well as:
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> #
on Odroid-C1

Thank you Uwe!


Best regards,
Martin

Re: [PATCH v2] hwrng: meson - Improve error handling for core clock

[Herbert Xu]

On Mon, Sep 20, 2021 at 09:44:05AM +0200, Uwe Kleine-König wrote:
> -ENOENT (ie. "there is no clock") is fine to ignore for an optional
> clock, other values are not supposed to be ignored and should be
> escalated to the caller (e.g. -EPROBE_DEFER). Ignore -ENOENT by using
> devm_clk_get_optional().
> 
> While touching this code also add an error message for the fatal errors.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
> Hello,
> 
> compared to (implicit) v1
> (https://lore.kernel.org/r/20210914142428.57099-1-u.kleine-koenig@pengutronix.de)
> this used dev_err_probe() as suggested by Martin Blumenstingl.
> 
> v1 got a "Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>", I didn't add
> that because of the above change.
> 
> (Hmm, my setup is broken, the b4 patch signature was done before I added this
> message. I wonder if this will break the signature ...)
> 
> Best regards
> Uwe
> 
>  drivers/char/hw_random/meson-rng.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt