On Thu, 4 Apr 2019, Jesse Hathaway wrote: > On Tue, Apr 2, 2019 at 9:29 AM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > Most likely the problem occurs somewhere inside > > quirk_usb_handoff_xhci(). Can Jesse add debugging statements to that > > routine in order to pin down exactly where the problem lies? > > Alan, > > I added debug statements to quirk_usb_early_handoff, quirk_usb_disable_ehci & > ehci_bios_handoff. The box hangs right before calling: > > pci_write_config_byte(pdev, offset + 3, 1); Right _before_ that line? Not _after_ it? That's surprising because the two preceding lines of code are the condition of an "if" statement and a dev_dbg() call. I don't see how either of them could cause a hang. Maybe the hang is a delayed reaction to something happening somewhere else. But on the assumption that it isn't, you could try commenting out various parts of ehci_bios_handoff to see which ones make a difference. > which is in ehci_bios_handoff: > > [ 10.698240] DEBUG: Passed quirk_usb_early_handoff 1300 > [ 10.704271] DEBUG: Passed quirk_usb_early_handoff 1308 > [ 10.710206] DEBUG: Passed quirk_usb_disable_ehci 939 > [ 10.715949] DEBUG: Passed quirk_usb_disable_ehci 945 > [ 10.721685] DEBUG: Passed quirk_usb_disable_ehci 950 > [ 10.727423] DEBUG: Passed quirk_usb_disable_ehci 958 > [ 10.733160] DEBUG: Passed quirk_usb_disable_ehci 964 > [ 10.738897] DEBUG: Passed quirk_usb_disable_ehci 968 > [ 10.744633] DEBUG: Passed ehci_bios_handoff 849 > [ 10.749884] DEBUG: Passed ehci_bios_handoff 884 > > I have attached the debug output, and my modified pci-quirks.c file > to the bug report, let me know what else I can do to help. Nothing was attached. Alan Stern