Re: [PATCH v5 3/7] pmdomain: rockchip: forward rockchip_do_pmu_set_power_domain errors

Peter Geis
2024-12-11T23:11:50Z

On Wed, Dec 11, 2024 at 3:46 PM Sebastian Reichel
<sebastian.reichel@collabora.com> wrote:
>
> Hello Peter,
>
> On Wed, Dec 11, 2024 at 02:53:34PM -0500, Peter Geis wrote:
> > On Wed, Dec 11, 2024 at 9:32 AM Sebastian Reichel
> > <sebastian.reichel@collabora.com> wrote:
> > >
> > > Currently rockchip_do_pmu_set_power_domain prints a warning if there
> > > have been errors turning on the power domain, but it does not return
> > > any errors and rockchip_pd_power() tries to continue setting up the
> > > QOS registers. This usually results in accessing unpowered registers,
> > > which triggers an SError and a full system hang.
> > >
> > > This improves the error handling by forwarding the error to avoid
> > > kernel panics.
> >
> > I think we should merge your patch here with my patch for returning
> > errors from rockchip_pmu_set_idle_request [1].
>
> I will have a look.
>
> > > Reviewed-by: Heiko Stuebner <heiko@sntech.de>
> > > Tested-by: Heiko Stuebner <heiko@sntech.de>
> > > Tested-by: Adrian Larumbe <adrian.larumbe@collabora.com> # On Rock 5B
> > > Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> > > ---
> > > drivers/pmdomain/rockchip/pm-domains.c | 34 +++++++++++++++++---------
> > > 1 file changed, 22 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/drivers/pmdomain/rockchip/pm-domains.c b/drivers/pmdomain/rockchip/pm-domains.c
> > > index a161ee13c633..8f440f2883db 100644
> > > --- a/drivers/pmdomain/rockchip/pm-domains.c
> > > +++ b/drivers/pmdomain/rockchip/pm-domains.c
> > > @@ -533,16 +533,17 @@ static int rockchip_pmu_domain_mem_reset(struct rockchip_pm_domain *pd)
> > > return ret;
> > > }
> > >
> > > -static void rockchip_do_pmu_set_power_domain(struct rockchip_pm_domain *pd,
> > > - bool on)
> > > +static int rockchip_do_pmu_set_power_domain(struct rockchip_pm_domain *pd,
> > > + bool on)
> > > {
> > > struct rockchip_pmu *pmu = pd->pmu;
> > > struct generic_pm_domain *genpd = &pd->genpd;
> > > u32 pd_pwr_offset = pd->info->pwr_offset;
> > > bool is_on, is_mem_on = false;
> > > + int ret;
> > >
> > > if (pd->info->pwr_mask == 0)
> > > - return;
> > > + return 0;
> > >
> > > if (on && pd->info->mem_status_mask)
> > > is_mem_on = rockchip_pmu_domain_is_mem_on(pd);
> > > @@ -557,16 +558,21 @@ static void rockchip_do_pmu_set_power_domain(struct rockchip_pm_domain *pd,
> > >
> > > wmb();
> > >
> > > - if (is_mem_on && rockchip_pmu_domain_mem_reset(pd))
> > > - return;
> > > + if (is_mem_on) {
> > > + ret = rockchip_pmu_domain_mem_reset(pd);
> > > + if (ret)
> > > + return ret;
> > > + }
> > >
> > > - if (readx_poll_timeout_atomic(rockchip_pmu_domain_is_on, pd, is_on,
> > > - is_on == on, 0, 10000)) {
> > > - dev_err(pmu->dev,
> > > - "failed to set domain '%s', val=%d\n",
> > > - genpd->name, is_on);
> > > - return;
> > > + ret = readx_poll_timeout_atomic(rockchip_pmu_domain_is_on, pd, is_on,
> > > + is_on == on, 0, 10000);
> > > + if (ret) {
> > > + dev_err(pmu->dev, "failed to set domain '%s' %s, val=%d\n",
> > > + genpd->name, on ? "on" : "off", is_on);
> > > + return ret;
> > > }
> > > +
> > > + return 0;
> > > }
> > >
> > > static int rockchip_pd_power(struct rockchip_pm_domain *pd, bool power_on)
> > > @@ -592,7 +598,11 @@ static int rockchip_pd_power(struct rockchip_pm_domain *pd, bool power_on)
> > > rockchip_pmu_set_idle_request(pd, true);
> > > }
> > >
> > > - rockchip_do_pmu_set_power_domain(pd, power_on);
> > > + ret = rockchip_do_pmu_set_power_domain(pd, power_on);
> > > + if (ret < 0) {
> > > + clk_bulk_disable(pd->num_clks, pd->clks);
> > > + return ret;
> >
> > Looking at it, we shouldn't return directly from here because the
> > mutex never gets unlocked.
>
> Yes, we should do that after patch 2/7 from this series :)

That's excellent!

>
> > Instead of repeating clk_bulk_disable and return ret for each failure,
> > we can initialize ret = 0, have a goto: out pointing to
> > clk_bulk_disable, and change return 0 to return ret at the end.
>
> Right now there is only a single clk_bulk_disable() in an error
> case, so I did not use the typical error goto chain. I suppose
> it makes a lot more sense with proper error handling for the calls
> to rockchip_pmu_set_idle_request().

If you'd like, I can base my v2 on this patch series with the changes
I'm suggesting?

>
> Greetings,
>
> -- Sebastian
>
> >
> > What do you think?
> >
> > Very Respectfully,
> > Peter Geis
> >
> > [1] https://lore.kernel.org/linux-rockchip/20241210013010.81257-2-pgwipeout@gmail.com/
> >
> > > + }
> > >
> > > if (power_on) {
> > > /* if powering up, leave idle mode */
> > > --
> > > 2.45.2
> > >
> > >
> > > _______________________________________________
> > > Linux-rockchip mailing list
> > > Linux-rockchip@lists.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-rockchip