[PATCH] PSCI: Print a warning if PSCI doesn't accept PC mode

[Dmitry Baryshkov]

On Thu, 28 Jul 2022 at 11:58, Sudeep Holla <sudeep.holla at arm.com> wrote:
>
> On Wed, Jul 27, 2022 at 09:20:34PM +0300, Dmitry Baryshkov wrote:
> > The function psci_pd_try_set_osi_mode() will print an error if enabling
> > OSI mode fails. To ease debugging PSCI issues print corresponding
> > message if switching to PC mode fails too.
> >
>
> Are you seeing that even setting to PC mode failing on msm8996. The platform
> must boot in PC mode, so even if it fails we ignore so not sure if the logging
> is of much help here IMO.

It helped me to understand that it is not only setting OSI, who fails
with the 'not_supported' status, but setting PC mode also fails. Which
later led me to checking which functions are provided at all, etc.

>
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> > ---
> >  drivers/firmware/psci/psci.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> > index cfb448eabdaa..b907768eea01 100644
> > --- a/drivers/firmware/psci/psci.c
> > +++ b/drivers/firmware/psci/psci.c
> > @@ -597,7 +597,9 @@ static int __init psci_1_0_init(struct device_node *np)
> >               pr_info("OSI mode supported.\n");
> >
> >               /* Default to PC mode. */
> > -             psci_set_osi_mode(false);
> > +             err = psci_set_osi_mode(false);
> > +             if (err)
> > +                     pr_info("setting PC mode failed with %d\n", err);
>
> Since we don't care about error value here, does it make sense to add the
> log in psci_set_osi_mode() that covers both PC and OSI case whenever it is
> called ?

Yes, this sounds like a logical idea. I'll do this in v2.

-- 
With best wishes
Dmitry