On Mon, 18 Aug 2014, Du, ChangbinX wrote: > > On Fri, 15 Aug 2014, Du, ChangbinX wrote: > > > If my analysis is correct, could you share your ideas for this issue? > > > > Hasn't this already been fixed? See commit d6236f6d1d88 (xhci: Fix runtime > > suspended xhci from blocking system suspend). > > > > Alan Stern > > Hi, Stern, > These are two different issues. Commit d6236f6d1d88 fixes issue that xhci > runtime > pm logical blocks system suspend. But the issue we are encountering is usb > device > resuming fail and lead to device reset.
Yes, the issues are different, but I think the fix is the same. You should test a kernel that includes commit d6236f6d1d88. > This issue can be reproduced by below steps: > 1) Plug a usb device to usb3 host, and make sure this device can enter runtime > suspend state. > 2) Wait HCD entering runtime suspend state.( xhci_suspend() will be called) > 3) Make system starts system suspending. On this step, PM core freeze threads > and > resume hcd & the usb device to runtime active state(xhci_resume() will be > called, > and roothub resuming work item is queued). Then calls the suspend callbacks > of devices'. Commit d6236f6d1d88 prevents the roothub resuming work item from being queued. > 4) We force system suspending process aborted (by modifying code) just after > the usb > Device suspend callback is invoked. > 5) Then PM core will call resume callback of the usb device to recovery. On > this step > usb_dev_resume() invokes and it return -113 error. Because the can_submit > flag of > root hub is 0. Root hub resuming work item is still pending. I still think that commit has already fixed your problem. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
