[PATCH] leds: qcom-lpg: Check the return value of regmap_bulk_write()

[PATCH] leds: qcom-lpg: Check the return value of regmap_bulk_write()

[Haotian Zhang]

The lpg_lut_store() function currently ignores the return value of
regmap_bulk_write() and always returns 0. This can cause hardware write
failures to go undetected, leading the caller to believe LUT programming
succeeded when it may have failed.

Check the return value of regmap_bulk_write() in lpg_lut_store and return
the error to the caller on failure.

Fixes: 24e2d05d1b68 ("leds: Add driver for Qualcomm LPG")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
---
 drivers/leds/rgb/leds-qcom-lpg.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
index 4f2a178e3d26..76734b1520f6 100644
--- a/drivers/leds/rgb/leds-qcom-lpg.c
+++ b/drivers/leds/rgb/leds-qcom-lpg.c
@@ -369,7 +369,7 @@ static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
 {
 	unsigned int idx;
 	u16 val;
-	int i;
+	int i, ret;
 
 	idx = bitmap_find_next_zero_area(lpg->lut_bitmap, lpg->lut_size,
 					 0, len, 0);
@@ -379,8 +379,10 @@ static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
 	for (i = 0; i < len; i++) {
 		val = pattern[i].brightness;
 
-		regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i),
+		ret = regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i),
 				  &val, sizeof(val));
+		if (ret)
+			return ret;
 	}
 
 	bitmap_set(lpg->lut_bitmap, idx, len);
-- 
2.50.1.windows.1

Re: [PATCH] leds: qcom-lpg: Check the return value of regmap_bulk_write()

[Lee Jones]

On Thu, 04 Dec 2025, Haotian Zhang wrote:

> The lpg_lut_store() function currently ignores the return value of
> regmap_bulk_write() and always returns 0. This can cause hardware write
> failures to go undetected, leading the caller to believe LUT programming
> succeeded when it may have failed.
> 
> Check the return value of regmap_bulk_write() in lpg_lut_store and return
> the error to the caller on failure.
> 
> Fixes: 24e2d05d1b68 ("leds: Add driver for Qualcomm LPG")
> Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
> ---
>  drivers/leds/rgb/leds-qcom-lpg.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
> index 4f2a178e3d26..76734b1520f6 100644
> --- a/drivers/leds/rgb/leds-qcom-lpg.c
> +++ b/drivers/leds/rgb/leds-qcom-lpg.c
> @@ -369,7 +369,7 @@ static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
>  {
>  	unsigned int idx;
>  	u16 val;
> -	int i;
> +	int i, ret;
>  
>  	idx = bitmap_find_next_zero_area(lpg->lut_bitmap, lpg->lut_size,
>  					 0, len, 0);
> @@ -379,8 +379,10 @@ static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
>  	for (i = 0; i < len; i++) {
>  		val = pattern[i].brightness;
>  
> -		regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i),
> +		ret = regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i),
>  				  &val, sizeof(val));

Fine, but you need to re-align this to the '(' above.

> +		if (ret)
> +			return ret;
>  	}
>  
>  	bitmap_set(lpg->lut_bitmap, idx, len);
> -- 
> 2.50.1.windows.1
> 

-- 
Lee Jones [李琼斯]

[PATCH v2] leds: qcom-lpg: Check the return value of regmap_bulk_write()

[Haotian Zhang]

The lpg_lut_store() function currently ignores the return value of
regmap_bulk_write() and always returns 0. This can cause hardware write
failures to go undetected, leading the caller to believe LUT programming
succeeded when it may have failed.

Check the return value of regmap_bulk_write() in lpg_lut_store and return
the error to the caller on failure.

Fixes: 24e2d05d1b68 ("leds: Add driver for Qualcomm LPG")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>

---
Changes in v2:
  - Fix indentation alignment.
---
 drivers/leds/rgb/leds-qcom-lpg.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
index 4f2a178e3d26..c33a49105dfc 100644
--- a/drivers/leds/rgb/leds-qcom-lpg.c
+++ b/drivers/leds/rgb/leds-qcom-lpg.c
@@ -369,7 +369,7 @@ static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
 {
 	unsigned int idx;
 	u16 val;
-	int i;
+	int i, ret;
 
 	idx = bitmap_find_next_zero_area(lpg->lut_bitmap, lpg->lut_size,
 					 0, len, 0);
@@ -379,8 +379,10 @@ static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
 	for (i = 0; i < len; i++) {
 		val = pattern[i].brightness;
 
-		regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i),
-				  &val, sizeof(val));
+		ret = regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i),
+					&val, sizeof(val));
+		if (ret)
+			return ret;
 	}
 
 	bitmap_set(lpg->lut_bitmap, idx, len);
-- 
2.50.1.windows.1

Re: (subset) [PATCH v2] leds: qcom-lpg: Check the return value of regmap_bulk_write()

[Lee Jones]

On Fri, 09 Jan 2026 01:51:33 +0800, Haotian Zhang wrote:
> The lpg_lut_store() function currently ignores the return value of
> regmap_bulk_write() and always returns 0. This can cause hardware write
> failures to go undetected, leading the caller to believe LUT programming
> succeeded when it may have failed.
> 
> Check the return value of regmap_bulk_write() in lpg_lut_store and return
> the error to the caller on failure.
> 
> [...]

Applied, thanks!

[1/1] leds: qcom-lpg: Check the return value of regmap_bulk_write()
      commit: 33e822f6f4eba2cfbd09ffd080af221cf8c542b2

--
Lee Jones [李琼斯]