[PATCH] thermal/drivers/mediatek/lvts_thermal: only update registered thermal zones

[Chen-Yu Tsai]

On Sun, Apr 2, 2023 at 4:34 AM Daniel Lezcano <daniel.lezcano at linaro.org> wrote:
>
> On 28/03/2023 05:10, Chen-Yu Tsai wrote:
> > It's possible for some sensors or thermal zones to not be registered,
> > either because they are unused or not fully declared in the device tree.
> > Nevertheless the driver enables interrupts for all sensors. If an
> > interrupt happens for an not-registered sensor, the driver would end up
> > updating a non-existent thermal zone, which leads to a NULL pointer
> > dereference.
> >
> > Change it so that only registered thermal zones get updated.
>
> Why not change the interrupt initialization ?

I'll send another patch for that.

However I think the part in this patch should still be fixed?

ChenYu

> > Fixes: f5f633b18234 ("thermal/drivers/mediatek: Add the Low Voltage Thermal Sensor driver")
> > Signed-off-by: Chen-Yu Tsai <wenst at chromium.org>
> > ---
> >   drivers/thermal/mediatek/lvts_thermal.c | 7 ++++++-
> >   1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c
> > index d87d3847c7d0..bf59174e18d3 100644
> > --- a/drivers/thermal/mediatek/lvts_thermal.c
> > +++ b/drivers/thermal/mediatek/lvts_thermal.c
> > @@ -415,9 +415,14 @@ static irqreturn_t lvts_ctrl_irq_handler(struct lvts_ctrl *lvts_ctrl)
> >               if (!(value & masks[i]))
> >                       continue;
> >
> > +             iret = IRQ_HANDLED;
> > +
> > +             /* sensor might not exist (bogus interrupt) or not be registered */
> > +             if (!lvts_ctrl->sensors[i].tz)
> > +                     continue;
> > +
> >               thermal_zone_device_update(lvts_ctrl->sensors[i].tz,
> >                                          THERMAL_TRIP_VIOLATED);
> > -             iret = IRQ_HANDLED;
> >       }
> >
> >       /*
>
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