Hi, On Wed, Aug 30, 2023 at 12:35 AM Sven van Ashbrook <svenva@xxxxxxxxxxxx> wrote: > > + Rafael for advice on runtime_pm corner cases. > > On Mon, Aug 28, 2023 at 10:48 PM Ben Chuang <benchuanggli@xxxxxxxxx> wrote: > > > > > > My concern is that when runtime_pm is false, gl9763e is disabled LPM > > negotiation, gl9763e can't enter L1.x and s0ix may fail. > > It seems that runtime_pm will always exist and that's ok. > > > > Thank you. I believe we can address your concern. > > - XXX_suspend/XXX_resume (i.e. classic suspend/resume) depends on > CONFIG_PM_SLEEP. This always selects CONFIG_PM. This always includes > the runtime_pm framework. So, if XXX_suspend/XXX_resume gets called, > the runtime_pm framework is always present, but may not be actively > managing the device. This is ok. > > - "when runtime_pm is false" AFAIK the only way to disable runtime_pm > when CONFIG_PM is set, is to write "on" to /sys/devices/.../power/control. > See https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-devices-power > In that case, the runtime_pm framework will activate the device, calling > XXX_runtime_resume() if necessary. Are there other ways of disabling it? > > - if /sys/devices/.../power/control is "on", then: > gl9763e_runtime_resume() always called -> LPM always disabled > gl9763e_suspend() -> LPM enabled -> gl9763e_resume() -> LPM disabled > In between "classic" XXX_suspend and XXX_resume, LPM will be enabled, > so the device can enter L1.x and S0ix. In this cas, after gl9763e_resume(), it is LPM disabled. Is there no chance for gl9763e to enter L1.x again when the system is idle? > > And the LPM negotiation flags look correct. > Does that address your concerns? Best regards, Ben Chuang
