| Message ID | 20200504104917.v6.1.Ic7096b3b9b7828cdd41cd5469a6dee5eb6abf549@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v6,1/5] soc: qcom: rpmh-rsc: Correctly ignore CPU_CLUSTER_PM notifications | expand |
Quoting Douglas Anderson (2020-05-04 10:50:15) > 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: Stephen Boyd <swboyd@chromium.org>
Hi, On Mon, May 4, 2020 at 10:50 AM Douglas Anderson <dianders@chromium.org> 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> > --- > > Changes in v6: > - Release the lock on cluster notifications. > > 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 | 3 +++ > 1 file changed, 3 insertions(+) The bugfixes in this series seem somewhat important to land. Is there something delaying them? Are we waiting for some tags from Maulik? -Doug
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c index a9e15699f55f..8c338335fc21 100644 --- a/drivers/soc/qcom/rpmh-rsc.c +++ b/drivers/soc/qcom/rpmh-rsc.c @@ -806,6 +806,9 @@ 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: + ret = NOTIFY_DONE; + goto exit; } 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> --- Changes in v6: - Release the lock on cluster notifications. 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 | 3 +++ 1 file changed, 3 insertions(+)