[PATCH] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()

[PATCH] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()

[Chen Ni]

The devm_gpiod_get_optional() function may return an ERR_PTR in case of
genuine GPIO acquisition errors, not just NULL which indicates the
legitimate absence of an optional GPIO.

Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On
error, return the error code to ensure proper failure handling rather
than proceeding with invalid pointers.

Fixes: e1915eec54a6 ("backlight: sky81452: Convert to GPIO descriptors")
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
---
 drivers/video/backlight/sky81452-backlight.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c
index 2749231f0385..e3e5306fab84 100644
--- a/drivers/video/backlight/sky81452-backlight.c
+++ b/drivers/video/backlight/sky81452-backlight.c
@@ -202,6 +202,10 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
 	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
 	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
 	pdata->gpiod_enable = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH);
+	if (IS_ERR(pdata->gpiod_enable)) {
+		dev_err(dev, "failed to get gpio\n");
+		return ERR_CAST(pdata->gpiod_enable);
+	}
 
 	ret = of_property_count_u32_elems(np, "led-sources");
 	if (ret < 0) {
-- 
2.25.1

Re: [PATCH] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()

[Daniel Thompson]

On Mon, Feb 02, 2026 at 03:54:10PM +0800, Chen Ni wrote:
> The devm_gpiod_get_optional() function may return an ERR_PTR in case of
> genuine GPIO acquisition errors, not just NULL which indicates the
> legitimate absence of an optional GPIO.
>
> Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On
> error, return the error code to ensure proper failure handling rather
> than proceeding with invalid pointers.
>
> Fixes: e1915eec54a6 ("backlight: sky81452: Convert to GPIO descriptors")
> Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
> ---
>  drivers/video/backlight/sky81452-backlight.c | 4 ++++
>  1 file changed, 4 insertions(+)

Thanks for the fix.

Small review comment below:

> diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c
> index 2749231f0385..e3e5306fab84 100644
> --- a/drivers/video/backlight/sky81452-backlight.c
> +++ b/drivers/video/backlight/sky81452-backlight.c
> @@ -202,6 +202,10 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
>  	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
>  	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
>  	pdata->gpiod_enable = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH);
> +	if (IS_ERR(pdata->gpiod_enable)) {
> +		dev_err(dev, "failed to get gpio\n");
> +		return ERR_CAST(pdata->gpiod_enable);
> +	}

Using dev_err_cast_probe() would make this change more compact and give
a better error message for the user.
>
>  	ret = of_property_count_u32_elems(np, "led-sources");
>  	if (ret < 0) {


Daniel.

[PATCH v2] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()

[Chen Ni]

The devm_gpiod_get_optional() function may return an ERR_PTR in case of
genuine GPIO acquisition errors, not just NULL which indicates the
legitimate absence of an optional GPIO.

Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On
error, return the error code to ensure proper failure handling rather
than proceeding with invalid pointers.

Fixes: e1915eec54a6 ("backlight: sky81452: Convert to GPIO descriptors")
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
---
Changes in v2:
- Use dev_err_cast_probe() to make the code more concise.
---
 drivers/video/backlight/sky81452-backlight.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c
index 2749231f0385..b2679b24de14 100644
--- a/drivers/video/backlight/sky81452-backlight.c
+++ b/drivers/video/backlight/sky81452-backlight.c
@@ -202,6 +202,9 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
 	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
 	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
 	pdata->gpiod_enable = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH);
+	if (IS_ERR(pdata->gpiod_enable))
+		return dev_err_cast_probe(dev, pdata->gpiod_enable,
+					  "failed to get gpio\n");
 
 	ret = of_property_count_u32_elems(np, "led-sources");
 	if (ret < 0) {
-- 
2.25.1

Re: [PATCH v2] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()

[Daniel Thompson]

On Tue, Feb 03, 2026 at 10:16:25AM +0800, Chen Ni wrote:
> The devm_gpiod_get_optional() function may return an ERR_PTR in case of
> genuine GPIO acquisition errors, not just NULL which indicates the
> legitimate absence of an optional GPIO.
>
> Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On
> error, return the error code to ensure proper failure handling rather
> than proceeding with invalid pointers.
>
> Fixes: e1915eec54a6 ("backlight: sky81452: Convert to GPIO descriptors")
> Signed-off-by: Chen Ni <nichen@iscas.ac.cn>

Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>


Daniel.

Re: [PATCH v2] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()

[Linus Walleij]

On Tue, Feb 3, 2026 at 3:17 AM Chen Ni <nichen@iscas.ac.cn> wrote:

> The devm_gpiod_get_optional() function may return an ERR_PTR in case of
> genuine GPIO acquisition errors, not just NULL which indicates the
> legitimate absence of an optional GPIO.
>
> Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On
> error, return the error code to ensure proper failure handling rather
> than proceeding with invalid pointers.
>
> Fixes: e1915eec54a6 ("backlight: sky81452: Convert to GPIO descriptors")
> Signed-off-by: Chen Ni <nichen@iscas.ac.cn>

Reviewed-by: Linus Walleij <linusw@kernel.org>

Yours,
Linus Walleij

Re: (subset) [PATCH v2] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()

[Lee Jones]

On Tue, 03 Feb 2026 10:16:25 +0800, Chen Ni wrote:
> The devm_gpiod_get_optional() function may return an ERR_PTR in case of
> genuine GPIO acquisition errors, not just NULL which indicates the
> legitimate absence of an optional GPIO.
> 
> Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On
> error, return the error code to ensure proper failure handling rather
> than proceeding with invalid pointers.
> 
> [...]

Applied, thanks!

[1/1] backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()
      commit: 797cc011ae02bda26f93d25a4442d7a1a77d84df

--
Lee Jones [李琼斯]