On Mon, Oct 11, 2021 at 01:10:18PM +0800, zhuyinbo wrote: > > 在 2021/10/10 上午3:39, Alan Stern 写道: > > On Sat, Oct 09, 2021 at 10:01:25AM +0800, zhuyinbo wrote: > > > 在 2021/10/8 下午10:26, Alan Stern 写道: > > > > On Fri, Oct 08, 2021 at 03:26:10PM +0800, Yinbo Zhu wrote: > > > > > The usb states of ohci controller include UsbOperational, UsbReset, > > > > > UsbSuspend and UsbResume. Among them, only the UsbOperational state > > > > > supports launching the start of frame for host controller according > > > > > the ohci protocol spec, but in S3/S4 press test procedure, it may > > > > Nobody reading this will know what "S3/S4 press test procedure" means. > > > > You have to explain it, or use a different name that people will > > > > understand. > > > okay, I got it. > > > > > happen that the start of frame was launched in other usb states and > > > > > cause ohci works abnormally then kernel will allways report rcu > > > > > call trace. This patch was to add check for host controller > > > > > functional states and if it is not UsbOperational state that need > > > > > set INTR_SF in intrdisable register to ensure SOF Token generation > > > > > was been disabled. > > > > This doesn't make sense. You already mentioned that only the > > > > UsbOperational state supports sending start-of-frame packets. So if the > > > > controller is in a different state then it won't send these packets, > > > > whether INTR_SF is enabled or not. > > > > > > > > What problem are you really trying to solve? > > > Only UsbOperational state supports sending start-of-frame packets, but in > > > fact, in S3/S4 press test procedure, > > > > > > usb in non-UsbOperational state that send start-of-frame packets but hc > > > driver doesn't deal with this frame. and hc will > > > > > > allways lauched the SOF for finishing the frame, the cpu will hand this sof > > > interrupt and doesn't deal with time interrupt > > > > > > that will cause rcu call trace then system doesn't suspend to memory/disk. > > I still don't understand. > > > > Are you saying that your OHCI controller behaves badly because it sends > > SOF packets even when the state is different from UsbOperational? > > HC will allways report the SoF interrupt in the all time when HC was not in > NO-UsbOperation state. How did your host controller get into the non-UsbOperational state? What part of the code is responsible for changing to a different state? It looks like the only place where this could happen is in ohci_rh_suspend(). So if you disable SOF interrupts there, it should fix your problem. > and no WritebackDoneHead interrupt that is the issue phenomenon. and this > situation is badly state for ohci. > > > > > > Hi Alan Stern, > > > > > > even though ed_rm_list is non-NULL, if hc in non-UsbOperation state set > > > SoF status in usbsts register that is illegal, > > > > > > at this time hcd doesn't need care URB whether finished, because hc had > > > into a wrong state. even thoug it doesn't has this patch, > > > > > > URB was not be able to finish when hc in above worng state. except software > > > can intervence this wrong state. but the SoF bit of usbsts > > > > > > register was set by HC, and this action will happen always !!! software > > > clear SoF state I think it isn't make sense. software only disable SoF > > > > > > interrupt to fix HC wrong state. > > This problem happens when you go into S3 or S4 suspend, right? So you > > should fix the problem by disabling INTR_SF when the root hub is > > suspended. Try adding > > > > /* All ED unlinks should be finished, no need for SOF interrupts */ > > ohci_writel(ohci, OHCI_INTR_SF, &ohci->regs->intrdisable); > > > > into ohci_rh_suspend(), just before the update_done_list() call. If you > > add this then INTR_SF will not be enabled during S3 or S4 suspend, so > > the problem shouldn't occur. Does that work for you? > > The system doesn't suspend to disk completely by my test result and hc will > always produce SoF interrupt. Have you tried adding those two lines of code shown above? If you haven't tested them, please don't write back until you have. Alan Stern
