Re: [PATCH RESEND 1/2] thermal: intel: Prevent accidental clearing of HFI status

From: Rafael J. Wysocki
Date: Wed Nov 23 2022 - 14:10:58 EST


On Fri, Nov 18, 2022 at 8:49 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
>
> On Fri, Nov 18, 2022 at 8:38 PM srinivas pandruvada
> <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:
> >
> > On Fri, 2022-11-18 at 18:54 +0100, Rafael J. Wysocki wrote:
> > > On Wed, Nov 16, 2022 at 3:54 AM Srinivas Pandruvada
> > > <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:
> > > >
> > > > When there is a package thermal interrupt with PROCHOT log, it will
> > > > be
> > > > processed and cleared. It is possible that there is an active HFI
> > > > event
> > > > status, which is about to get processed or getting processed. While
> > > > clearing PROCHOT log bit, it will also clear HFI status bit. This
> > > > means
> > > > that hardware is free to update HFI memory.
> > > >
> > > > When clearing a package thermal interrupt, some processors will
> > > > generate
> > > > a "general protection fault" when any of the read only bit is set
> > > > to 1.
> > > > The driver maintains a mask of all read-write bits which can be
> > > > set.
> > > > This mask doesn't include HFI status bit. This bit will also be
> > > > cleared,
> > > > as it will be assumed read-only bit. So, add HFI status bit 26 to
> > > > the
> > > > mask.
> > > >
> > > > Signed-off-by: Srinivas Pandruvada
> > > > <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> > > > Reviewed-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
> > >
> > > Is a Fixes tag missing here?
> > While adding the following change, this should have been take care of:
> > ab09b0744a99 ("thermal: intel: hfi: Enable notification interrupt")
> >
> > But the above change didn't add this line, which this patch is
> > changing. We can add:
> >
> > Fixes: ab09b0744a99 ("thermal: intel: hfi: Enable notification
> > interrupt")
>
> OK
>
> > Do you want me to send another PATCH with fixes.
>
> No, I can take care of this.
>
> > >
> > > Also, do you want it in 6.1-rc7 or would 6.2 suffice?
> > Not urgent. 6.2 should be fine.
>
> OK, thanks!

Both applied as 6.2 material now, thanks!