Messages in this thread | | | Subject | Re: [PATCH] PM: runtime: Use pmruntime sync variant to put suppliers | From | Stanimir Varbanov <> | Date | Thu, 8 Oct 2020 04:08:06 +0300 |
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Hi Rafael,
On 10/7/20 5:37 PM, Rafael J. Wysocki wrote: > On Wed, Oct 7, 2020 at 2:20 AM Stanimir Varbanov > <stanimir.varbanov@linaro.org> wrote: >> >> Calling pm_runtime_put_sync over a device with suppliers with device >> link flags PM_RUNTIME | RPM_ACTIVE it is observed that the supplier >> is not put (turned off) at the end, but instead put asynchronously. > > Yes, that's by design. > >> In some case This could lead to issues for the callers which expects >> that the pmruntime sync variants should also put the suppliers >> synchronously. > > Why would anyone expect that to happen?
It is logical to me that when I call pm_runtime_put_sync the device and its suppliers are put synchronously. If I want to put device and its suppliers asynchronously I'd use pm_runtime_put. Is that wrong assumption?
> >> Also the opposite rpm_get_suppliers is already using pmruntime _sync >> variant of the API. > > Yes, it does, because that is necessary. > >> Correct this by changing pmruntime_put to pmruntime_put_sync in >> rpm_put_suppliers. > > It is not a correction, but a change in behavior without good enough > rationale, as it stands.
In my driver case I want to deal with a recovery of a crash in remote processor (the remote processor is used to control and program hardware blocks and also to communicate with host processor through shared memory). To restart the remote processor I have to disable clocks and turn off few power domains (one of the power domains is made a supplier of my main device) in order to complete the cold-boot.
The problem I'm facing with this design is that when I call runtime_put_sync (to disable device's clocks and turn off power domain) the clocks are disabled (part of pmruntime_suspend callback) but the pmdomain (the device supplier) is not turned synchronously. I workaround this by checking the supplier device via pm_runtime_active() until it becomes inactive and the continue with rest of the steps.
From my point of view this check for supplier activity should be part of pmruntime API.
> > Thanks! >
-- regards, Stan
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