Re: [PATCH 1/3] hwmon: (dell-smm) Fail probing when cooling device registration fails

[Armin Wolf]

Am 21.08.22 um 17:41 schrieb Pali Rohár:

> On Sunday 21 August 2022 17:17:11 Armin Wolf wrote:
> > Previously, it was thought that failing to register a cooling device
> > would not be critical, so the probing was not aborted in such a case.
> > This however would lead to userspace being unable to rely on those
> > cooling devices, since they might not represent all fans being present.
> > Fix that by failing probing when cooling device registration fails.
> This patch does not fix address this issue fully. CONFIG_THERMAL can be
> disabled during compile time and then cooling device would not be
> registered too.

I though of the cooling device feature as being optional "as a whole".
So when CONFIG_THERMAL is disabled during compile time, the driver does
not create any cooling devices. If however CONFIG_THERMAL was enabled
during compile time, the driver should fail probing if it cannot register
all cooling devices.

Armin Wolf

> > Tested on a Dell Inspiron 3505.
> >
> > Fixes: e0d3f7cb2606 ("hwmon: (dell-smm) Add cooling device support")
> > Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
> > ---
> >   drivers/hwmon/dell-smm-hwmon.c | 4 +---
> >   1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
> > index 7f8d95dd2717..1dab7591576a 100644
> > --- a/drivers/hwmon/dell-smm-hwmon.c
> > +++ b/drivers/hwmon/dell-smm-hwmon.c
> > @@ -1013,12 +1013,10 @@ static int __init dell_smm_init_hwmon(struct device *dev)
> >
> >   		data->fan[i] = true;
> >
> > -		/* the cooling device is not critical, ignore failures */
> >   		if (IS_REACHABLE(CONFIG_THERMAL)) {
> >   			err = dell_smm_init_cdev(dev, i);
> >   			if (err < 0)
> > -				dev_warn(dev, "Failed to register cooling device for fan %u\n",
> > -					 i + 1);
> > +				return err;
> >   		}
> >
> >   		data->fan_nominal_speed[i] = devm_kmalloc_array(dev, data->i8k_fan_max + 1,
> > --
> > 2.30.2