| Message ID | 20200424094610.v5.1.Ic7096b3b9b7828cdd41cd5469a6dee5eb6abf549@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v5,1/5] soc: qcom: rpmh-rsc: Correctly ignore CPU_CLUSTER_PM notifications | expand |
Hi, On 4/24/2020 10:16 PM, Douglas Anderson wrote: > Our switch statement doesn't have entries for CPU_CLUSTER_PM_ENTER, > CPU_CLUSTER_PM_ENTER_FAILED, and CPU_CLUSTER_PM_EXIT and doesn't have > a default. This means that we'll try to do a flush in those cases but > we won't necessarily be the last CPU down. That's not so ideal since > our (lack of) locking assumes we're on the last CPU. > > Luckily this isn't as big a problem as you'd think since (at least on > the SoC I tested) we don't get these notifications except on full > system suspend. ...and on full system suspend we get them on the last > CPU down. That means that the worst problem we hit is flushing twice. > Still, it's good to make it correct. > > Fixes: 985427f997b6 ("soc: qcom: rpmh: Invoke rpmh_flush() for dirty caches") > Reported-by: Stephen Boyd <swboyd@chromium.org> > Signed-off-by: Douglas Anderson <dianders@chromium.org> > Reviewed-by: Maulik Shah <mkshah@codeaurora.org> > Reviewed-by: Stephen Boyd <swboyd@chromium.org> > --- > > Changes in v5: > - Corrently => Correctly > > Changes in v4: > - ("...Corrently ignore CPU_CLUSTER_PM notifications") split out for v4. > > Changes in v3: None > Changes in v2: None > > drivers/soc/qcom/rpmh-rsc.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c > index a9e15699f55f..3571a99fc839 100644 > --- a/drivers/soc/qcom/rpmh-rsc.c > +++ b/drivers/soc/qcom/rpmh-rsc.c > @@ -806,6 +806,8 @@ static int rpmh_rsc_cpu_pm_callback(struct notifier_block *nfb, > case CPU_PM_EXIT: > cpumask_clear_cpu(smp_processor_id(), &drv->cpus_entered_pm); > goto exit; > + default: > + return NOTIFY_DONE; I noticed a bug here, Either need to unlock and return here. + default: + ret = NOTIFY_DONE; + goto exit; Or If you move this patch at the end of series, it should will work fine as is. Since in patch 5 of this series, pm_lock is removed, so return NOTIFY_DONE; do not any unlock. When i pulled in only first two changes in this series i got spinlock recursion during suspend-resume. Back when i pull in entire series for validation, the issue do not come because last patch removes pm_lock. Thanks, Maulik > } > > ret = rpmh_rsc_ctrlr_is_busy(drv);
Hi, On Sun, May 3, 2020 at 10:19 PM Maulik Shah <mkshah@codeaurora.org> wrote: > > Hi, > > On 4/24/2020 10:16 PM, Douglas Anderson wrote: > > Our switch statement doesn't have entries for CPU_CLUSTER_PM_ENTER, > > CPU_CLUSTER_PM_ENTER_FAILED, and CPU_CLUSTER_PM_EXIT and doesn't have > > a default. This means that we'll try to do a flush in those cases but > > we won't necessarily be the last CPU down. That's not so ideal since > > our (lack of) locking assumes we're on the last CPU. > > > > Luckily this isn't as big a problem as you'd think since (at least on > > the SoC I tested) we don't get these notifications except on full > > system suspend. ...and on full system suspend we get them on the last > > CPU down. That means that the worst problem we hit is flushing twice. > > Still, it's good to make it correct. > > > > Fixes: 985427f997b6 ("soc: qcom: rpmh: Invoke rpmh_flush() for dirty caches") > > Reported-by: Stephen Boyd <swboyd@chromium.org> > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > > Reviewed-by: Maulik Shah <mkshah@codeaurora.org> > > Reviewed-by: Stephen Boyd <swboyd@chromium.org> > > --- > > > > Changes in v5: > > - Corrently => Correctly > > > > Changes in v4: > > - ("...Corrently ignore CPU_CLUSTER_PM notifications") split out for v4. > > > > Changes in v3: None > > Changes in v2: None > > > > drivers/soc/qcom/rpmh-rsc.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c > > index a9e15699f55f..3571a99fc839 100644 > > --- a/drivers/soc/qcom/rpmh-rsc.c > > +++ b/drivers/soc/qcom/rpmh-rsc.c > > @@ -806,6 +806,8 @@ static int rpmh_rsc_cpu_pm_callback(struct notifier_block *nfb, > > case CPU_PM_EXIT: > > cpumask_clear_cpu(smp_processor_id(), &drv->cpus_entered_pm); > > goto exit; > > + default: > > + return NOTIFY_DONE; > > I noticed a bug here, > > Either need to unlock and return here. Dang it! Thank you very much for noticing. v6 sent. I removed both yours and Stephen's "Reviewed-by" tags. Please re-review to make sure I didn't do anything else stuid. > + default: > + ret = NOTIFY_DONE; > + goto exit; > > Or > > If you move this patch at the end of series, it should will work fine as is. > Since in patch 5 of this series, pm_lock is removed, so return > NOTIFY_DONE; do not any unlock. Right. It used to be part of the last patch but Stephen requested I move the bugfixes first so they could land sooner even if we aren't ready to land the "remove the pm_lock" patch. > When i pulled in only first two changes in this series i got spinlock > recursion during suspend-resume. > Back when i pull in entire series for validation, the issue do not come > because last patch removes pm_lock. OK, v6 is sent out. -Doug
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c index a9e15699f55f..3571a99fc839 100644 --- a/drivers/soc/qcom/rpmh-rsc.c +++ b/drivers/soc/qcom/rpmh-rsc.c @@ -806,6 +806,8 @@ static int rpmh_rsc_cpu_pm_callback(struct notifier_block *nfb, case CPU_PM_EXIT: cpumask_clear_cpu(smp_processor_id(), &drv->cpus_entered_pm); goto exit; + default: + return NOTIFY_DONE; } ret = rpmh_rsc_ctrlr_is_busy(drv);
Our switch statement doesn't have entries for CPU_CLUSTER_PM_ENTER, CPU_CLUSTER_PM_ENTER_FAILED, and CPU_CLUSTER_PM_EXIT and doesn't have a default. This means that we'll try to do a flush in those cases but we won't necessarily be the last CPU down. That's not so ideal since our (lack of) locking assumes we're on the last CPU. Luckily this isn't as big a problem as you'd think since (at least on the SoC I tested) we don't get these notifications except on full system suspend. ...and on full system suspend we get them on the last CPU down. That means that the worst problem we hit is flushing twice. Still, it's good to make it correct. Fixes: 985427f997b6 ("soc: qcom: rpmh: Invoke rpmh_flush() for dirty caches") Reported-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Maulik Shah <mkshah@codeaurora.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> --- Changes in v5: - Corrently => Correctly Changes in v4: - ("...Corrently ignore CPU_CLUSTER_PM notifications") split out for v4. Changes in v3: None Changes in v2: None drivers/soc/qcom/rpmh-rsc.c | 2 ++ 1 file changed, 2 insertions(+)