Re: [PATCH 4/5] thermal/core: Enforce paired .bind/.unbind callbacks

From: Zhang, Rui
Date: Mon Mar 27 2023 - 11:04:50 EST


On Fri, 2023-03-24 at 14:24 +0100, Rafael J. Wysocki wrote:
> On Fri, Mar 24, 2023 at 8:08 AM Zhang Rui <rui.zhang@xxxxxxxxx>
> wrote:
> > The .bind/.unbind callbacks are designed to allow the thermal zone
> > device to bind to/unbind from a matched cooling device, with
> > thermal
> > instances created/deleted.
> >
> > In this sense, .bind/.unbind callbacks must exist in pairs.
> >
> > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
> > ---
> > drivers/thermal/thermal_core.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/thermal/thermal_core.c
> > b/drivers/thermal/thermal_core.c
> > index 5225d65fb0e0..9c447f22cb39 100644
> > --- a/drivers/thermal/thermal_core.c
> > +++ b/drivers/thermal/thermal_core.c
> > @@ -1258,6 +1258,11 @@
> > thermal_zone_device_register_with_trips(const char *type, struct
> > thermal_trip *t
> > if (num_trips > 0 && (!ops->get_trip_type || !ops-
> > >get_trip_temp) && !trips)
> > return ERR_PTR(-EINVAL);
> >
> > + if ((ops->bind && !ops->unbind) || (!ops->bind && ops-
> > >unbind)) {
>
> This can be written as
>
> if (!!ops->bind != !!ops->unbind) {
>
> > + pr_err("Thermal zone device .bind/.unbind not
> > paired\n");
>
> And surely none of the existing drivers do that? Because it would be
> a functional regression if they did.

Yeah, I did a check and all drivers provide .bind/.unbind callbacks in
pairs.

Hi, Daniel,
I know you're dealing with various of thermal drivers recently, are you
aware of any exceptions?

thanks,
rui