Hi Felipe, On 13 May 2016 at 20:46, Felipe Balbi <balbi@xxxxxxxxxx> wrote: > > Hi, > > Baolin Wang <baolin.wang@xxxxxxxxxx> writes: >>>>> why does it need restart? Why is dwc3 powered off? Who powers it off? >>>> >>>> Because when the dwc3 Vbus is off (no cable pluging in now), >>>> especially for some mobile device, the system need to power off the >>>> dwc3 to save power in this situation. >>> >>> but dwc3 doesn't do this by itself, so who's doing it? >> >> Yes, the dwc3 clock is controlled by the Soc system, so the Soc system >> can disable the dwc3 clock when there is no cable plugging in. > > understood. > >>>>> This looks like a *really* bad power management implementation. Do you >>>>> have hibernation enabled? Do you have Clock gating enabled? Which dwc3 >>>>> version are you using? How was it configured? >>>> >>>> This is not hibernation, we want to power off the dwc3 to save power >>>> when no cable plugging in. Yes, we have clock gating, at this >>>> situation we will disable the clock and shutdown the phy to save >>>> power. For mobile device, most time no cable plugging in, so we need >>>> to think about the power consuming. How do you think this requirement? >>> >>> Well, seems like you're missing *proper* runtime PM. I've been meaning >>> to work on it for weeks, but I still have a few other things to do >>> before I get to that. In any case, we don't need to do what you did >>> here. There are better ways. >> >> Make sense. > > cool, if you wanna work on it, let me know and I can give some details > of what I have in mind. Could you explain details to me, and I wanna continue to optimize the power management things. Thanks. > > -- > balbi -- Baolin.wang Best Regards -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
