On 27.03.2023 12:10, Manivannan Sadhasivam wrote: > On Mon, Mar 27, 2023 at 11:24:58AM +0200, Konrad Dybcio wrote: >> >> >> On 27.03.2023 11:17, Manivannan Sadhasivam wrote: >>> On Mon, Mar 27, 2023 at 11:01:35AM +0200, Konrad Dybcio wrote: >>>> >>>> >>>> On 25.03.2023 17:52, Manivannan Sadhasivam wrote: >>>>> Hi, >>>>> >>>>> This series allows the dwc3-qcom driver to do runtime PM itself without >>>>> userspace intervention. Still, userspace is required to enable runtime PM >>>>> for dwc3 glue and xhci drivers as we cannot enable runtime PM for them. >>>>> But this series avoids one more additional step. >>>> What sort of 'userspace intervention' are we talking about? >>>> echo mem > /sys/power/state? >>>> >>> >>> I forgot to add that bit: >>> >>> echo auto > /sys/devices/platform/soc@0/a8f8800.usb/a800000.usb/xhci-hcd.1.auto/power/control >>> echo auto > /sys/devices/platform/soc@0/a8f8800.usb/a800000.usb/power/control >>> >>> You need to set "auto" for the runtime control for both xhci and dwc drivers. >>> >>> Then if you don't connect a usb device, all 3 drivers (dwc3-qcom, dwc3, and >>> xhci) will become runtime suspended after a delay of 5s (default delay). >>> >>> This can be confirmed by: >>> >>> cat /sys/devices/platform/soc@0/a8f8800.usb/power/runtime_status >>> >>> After connecting a usb device, they will all become "active". >> Thanks! And if I'm following correctly, we can't enable runtime PM >> for the DWC3 glue and XHCI drivers, as that would cause havoc on >> other, non-qc platforms. Is that correct? >> > > Kind of. Actually dwc3 glue is our qcom driver, other one is just dwc3 driver. > > The havoc would apply to xhci driver because, once it is suspended, one of its > parent drivers has to resume it. And that requires runtime PM support for all > the parent drivers which is currently not available. Makes sense, thanks for the explanation! > > But for dwc3 driver, I'm not sure about the consequence though. Maybe I should > send it as a separate patch later on and see what other platforms folks think > of it. May be worth a shot! Konrad > > Thanks, > Mani > >> Konrad >>> >>> Thanks, >>> Mani >>> >>>> Konrad >>>>> >>>>> While enabling runtime PM, I noticed that the xhci driver suspends before >>>>> catching the xhci interrupts during resume. This ended up deferring the >>>>> device enumeration for some time. So I included a patch adding autosuspend >>>>> delay of 200ms to the xhci driver. With this delay, usb enumeration happens >>>>> properly. >>>>> >>>>> This series has been tested on SC8280XP-CRD and RB5 devices. >>>>> >>>>> Thanks, >>>>> Mani >>>>> >>>>> Manivannan Sadhasivam (5): >>>>> arm64: dts: qcom: sc8280xp: Add missing dwc3 quirks >>>>> xhci: host: Use 200ms autosuspend delay for runtime suspend >>>>> usb: dwc3: qcom: Fix null ptr access during runtime_suspend() >>>>> usb: dwc3: qcom: Clear pending interrupt before enabling wake >>>>> interrupt >>>>> usb: dwc3: qcom: Allow runtime PM >>>>> >>>>> arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 14 ++++++++++++++ >>>>> drivers/usb/dwc3/dwc3-qcom.c | 13 +++++++++---- >>>>> drivers/usb/host/xhci-plat.c | 2 ++ >>>>> 3 files changed, 25 insertions(+), 4 deletions(-) >>>>> >>> >
