Re: [PATCH v2] iio: chemical: scd30: Use devm_mutex_init() over non-devm mutex_init()

[Jonathan Cameron]

On Thu, 4 Jun 2026 11:21:07 -0500
Maxwell Doose <m32285159@xxxxxxxxx> wrote:

> On Thu, Jun 4, 2026 at 11:20 AM David Lechner <dlechner@xxxxxxxxxxxx> wrote:
> >
> > On Thu, Jun 4, 2026 at 3:17 PM Maxwell Doose <m32285159@xxxxxxxxx> wrote:  
> > >
> > > The current code uses mutex_init() instead of devm_mutex_init(), which
> > > is incorrect as the rest of the file uses the devm automatic resource
> > > management API. Fix this so that the mutex is set up in the same way as
> > > the rest of the device data structure.
> > >
> > > Signed-off-by: Maxwell Doose <m32285159@xxxxxxxxx>
> > > ---
> > >  v2:
> > >  - Drop fixes tag per Jonathan's suggestion.
> > >  - Replace dev_err_probe() with return -ENOMEM per Jonathan and Andy's
> > >    suggestions.
> > >
> > >  drivers/iio/chemical/scd30_core.c | 5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/iio/chemical/scd30_core.c b/drivers/iio/chemical/scd30_core.c
> > > index db5cc295aeab..198add58affd 100644
> > > --- a/drivers/iio/chemical/scd30_core.c
> > > +++ b/drivers/iio/chemical/scd30_core.c
> > > @@ -714,7 +714,10 @@ int scd30_probe(struct device *dev, int irq, const char *name, void *priv,
> > >         state->pressure_comp = SCD30_PRESSURE_COMP_DEFAULT;
> > >         state->meas_interval = SCD30_MEAS_INTERVAL_DEFAULT;
> > >         state->command = command;
> > > -       mutex_init(&state->lock);
> > > +       ret = devm_mutex_init(dev, &state->lock);
> > > +       if (ret)
> > > +               return -ENOMEM;  
> >
> > Why are we ignoring ret?
> >
> > I would expect:
> >
> >               return ret;
> >  
> 
> Gah, I must've Jonathan's + Andy's comments get to my head (He said it
> should likely only return -ENOMEM) :(
> I don't know if he'll want to tweak while applying or if I should just
> go back and resubmit.

IIO is effectively closed for this cycle so plenty of time and I'm lazy
so please send a v3.

Jonathan