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

[Jonathan Cameron]

On Mon, 13 Jul 2026 15:36:51 +0300
Andy Shevchenko <andriy.shevchenko@xxxxxxxxx> wrote:

> 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.
I merged a slight variant on what Andy has here to keep the greendata
assignment and check closer together.

diff --git a/drivers/iio/light/ltrf216a.c b/drivers/iio/light/ltrf216a.c
index aad96fc91565..dd8f3260b1d8 100644
--- a/drivers/iio/light/ltrf216a.c
+++ b/drivers/iio/light/ltrf216a.c
@@ -248,11 +248,10 @@ static int ltrf216a_get_lux(struct ltrf216a_data *data)
                return ret;
 
        greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0);
+       ltrf216a_set_power_state(data, false);
        if (greendata < 0)
                return greendata;
 
-       ltrf216a_set_power_state(data, false);
-
        lux = greendata * data->info->lux_multiplier * LTRF216A_WIN_FAC;
 
        return lux;




> 
>