[PATCH] iio: light: ltrf216a: fix runtime PM reference leak in error path

[PATCH] iio: light: ltrf216a: fix runtime PM reference leak in error path

[Vidhu Sarwal]

ltrf216a_get_lux() acquires a runtime PM reference by calling
ltrf216a_set_power_state(data, true). However, if
ltrf216a_read_data() fails, the function returns immediately without
dropping the reference.

This leaves the runtime PM usage count unbalanced, preventing the device
from autosuspending after a failed read.

Fix this by releasing the runtime PM reference before returning from the
error path.

Fixes: 83f0bcd40d5c ("iio: light: Add support for ltrf216a sensor")
Signed-off-by: Vidhu Sarwal <vidhu.linux@gmail.com>
---
 drivers/iio/light/ltrf216a.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/light/ltrf216a.c b/drivers/iio/light/ltrf216a.c
index 3f34ddc911b4..3ec239eb5831 100644
--- a/drivers/iio/light/ltrf216a.c
+++ b/drivers/iio/light/ltrf216a.c
@@ -247,8 +247,10 @@ static int ltrf216a_get_lux(struct ltrf216a_data *data)
 		return ret;
 
 	greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0);
-	if (greendata < 0)
+	if (greendata < 0) {
+		ltrf216a_set_power_state(data, false);
 		return greendata;
+	}
 
 	ltrf216a_set_power_state(data, false);
 

base-commit: a13c140cc289c0b7b3770bce5b3ad42ab35074aa
-- 
2.53.0

Re: [PATCH] iio: light: ltrf216a: fix runtime PM reference leak in error path

[Joshua Crofts]

On Mon, 13 Jul 2026 07:58:29 +0530
Vidhu Sarwal <vidhu.linux@gmail.com> wrote:

> ltrf216a_get_lux() acquires a runtime PM reference by calling
> ltrf216a_set_power_state(data, true). However, if
> ltrf216a_read_data() fails, the function returns immediately without
> dropping the reference.
> 
> This leaves the runtime PM usage count unbalanced, preventing the device
> from autosuspending after a failed read.
> 
> Fix this by releasing the runtime PM reference before returning from the
> error path.
> 
> Fixes: 83f0bcd40d5c ("iio: light: Add support for ltrf216a sensor")
> Signed-off-by: Vidhu Sarwal <vidhu.linux@gmail.com>
> ---
>  drivers/iio/light/ltrf216a.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/light/ltrf216a.c b/drivers/iio/light/ltrf216a.c
> index 3f34ddc911b4..3ec239eb5831 100644
> --- a/drivers/iio/light/ltrf216a.c
> +++ b/drivers/iio/light/ltrf216a.c
> @@ -247,8 +247,10 @@ static int ltrf216a_get_lux(struct ltrf216a_data *data)
>  		return ret;
>  
>  	greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0);
> -	if (greendata < 0)
> +	if (greendata < 0) {
> +		ltrf216a_set_power_state(data, false);
>  		return greendata;
> +	}
>  
>  	ltrf216a_set_power_state(data, false);

LGTM, Sashiko had an issue with the fact that pm_runtime_mark_last_busy() isn't
called before autosuspending, however pm_runtime_put_autosuspend() already calls
this function in its body.

Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>

-- 
Kind regards

CJD

Re: [PATCH] iio: light: ltrf216a: fix runtime PM reference leak in error path

[Andy Shevchenko]

On Mon, Jul 13, 2026 at 07:58:29AM +0530, Vidhu Sarwal wrote:
> ltrf216a_get_lux() acquires a runtime PM reference by calling
> ltrf216a_set_power_state(data, true). However, if
> ltrf216a_read_data() fails, the function returns immediately without
> dropping the reference.
> 
> This leaves the runtime PM usage count unbalanced, preventing the device
> from autosuspending after a failed read.
> 
> Fix this by releasing the runtime PM reference before returning from the
> error path.

...

> static int ltrf216a_get_lux(struct ltrf216a_data *data)

>  	greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0);
> -	if (greendata < 0)
> +	if (greendata < 0) {
> +		ltrf216a_set_power_state(data, false);
>  		return greendata;
> +	}
>  
>  	ltrf216a_set_power_state(data, false);

Wouldn't be simpler to do

	greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0);

	ltrf216a_set_power_state(data, false);

	if (greendata < 0)
		return greendata;

?

Not insisting on this. Up to Jonathan and others to decide.


-- 
With Best Regards,
Andy Shevchenko