* [PATCH] hwrng: meson - Improve error handling for core clock
@ 2021-09-14 14:24 Uwe Kleine-König
2021-09-15 8:13 ` Neil Armstrong
2021-09-19 20:07 ` Martin Blumenstingl
0 siblings, 2 replies; 3+ messages in thread
From: Uwe Kleine-König @ 2021-09-14 14:24 UTC (permalink / raw)
To: Matt Mackall, Herbert Xu, Neil Armstrong, Kevin Hilman
Cc: Jerome Brunet, Martin Blumenstingl, linux-crypto,
linux-arm-kernel, linux-amlogic, kernel
-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>
---
drivers/char/hw_random/meson-rng.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
index e446236e81f2..9f3e2eb8011d 100644
--- a/drivers/char/hw_random/meson-rng.c
+++ b/drivers/char/hw_random/meson-rng.c
@@ -54,9 +54,15 @@ 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");
- if (IS_ERR(data->core_clk))
- data->core_clk = NULL;
+ data->core_clk = devm_clk_get_optional(dev, "core");
+ if (IS_ERR(data->core_clk)) {
+ ret = PTR_ERR(data->core_clk);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Failed to get core clock: %pe\n",
+ data->core_clk);
+
+ return ret;
+ }
if (data->core_clk) {
ret = clk_prepare_enable(data->core_clk);
--
2.30.2
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^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] hwrng: meson - Improve error handling for core clock
2021-09-14 14:24 [PATCH] hwrng: meson - Improve error handling for core clock Uwe Kleine-König
@ 2021-09-15 8:13 ` Neil Armstrong
2021-09-19 20:07 ` Martin Blumenstingl
1 sibling, 0 replies; 3+ messages in thread
From: Neil Armstrong @ 2021-09-15 8:13 UTC (permalink / raw)
To: Uwe Kleine-König, Matt Mackall, Herbert Xu, Kevin Hilman
Cc: Jerome Brunet, Martin Blumenstingl, linux-crypto,
linux-arm-kernel, linux-amlogic, kernel
On 14/09/2021 16:24, 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>
> ---
> drivers/char/hw_random/meson-rng.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
> index e446236e81f2..9f3e2eb8011d 100644
> --- a/drivers/char/hw_random/meson-rng.c
> +++ b/drivers/char/hw_random/meson-rng.c
> @@ -54,9 +54,15 @@ 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");
> - if (IS_ERR(data->core_clk))
> - data->core_clk = NULL;
> + data->core_clk = devm_clk_get_optional(dev, "core");
> + if (IS_ERR(data->core_clk)) {
> + ret = PTR_ERR(data->core_clk);
> + if (ret != -EPROBE_DEFER)
> + dev_err(dev, "Failed to get core clock: %pe\n",
> + data->core_clk);
> +
> + return ret;
> + }
>
> if (data->core_clk) {
> ret = clk_prepare_enable(data->core_clk);
>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Thanks,
Neil
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] hwrng: meson - Improve error handling for core clock
2021-09-14 14:24 [PATCH] hwrng: meson - Improve error handling for core clock Uwe Kleine-König
2021-09-15 8:13 ` Neil Armstrong
@ 2021-09-19 20:07 ` Martin Blumenstingl
1 sibling, 0 replies; 3+ messages in thread
From: Martin Blumenstingl @ 2021-09-19 20:07 UTC (permalink / raw)
To: Uwe Kleine-König
Cc: Matt Mackall, Herbert Xu, Neil Armstrong, Kevin Hilman,
Jerome Brunet, linux-crypto, linux-arm-kernel, linux-amlogic,
kernel
Hi Uwe,
On Tue, Sep 14, 2021 at 4:24 PM Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> wrote:
[...]
> - data->core_clk = devm_clk_get(dev, "core");
> - if (IS_ERR(data->core_clk))
> - data->core_clk = NULL;
> + data->core_clk = devm_clk_get_optional(dev, "core");
> + if (IS_ERR(data->core_clk)) {
> + ret = PTR_ERR(data->core_clk);
> + if (ret != -EPROBE_DEFER)
> + dev_err(dev, "Failed to get core clock: %pe\n",
> + data->core_clk);
> +
> + return ret;
I suggest simplifying this by using dev_err_probe as this:
- allows you to get rid of the if (ret != -EPROBE_DEFER)
- means that the message is shown in debugfs' "devices_deferred"
Best regards,
Martin
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2021-09-15 8:13 ` Neil Armstrong
2021-09-19 20:07 ` Martin Blumenstingl
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