Hi, Baolin Wang 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. -- balbi