Hello Dries and Tilman, Thank you for providing the logs and other relevant information. For clarification, when you were testing if the issue still exists, was this from cold boot or warm boot?
And if you sometimes see it working from cold boot it indeed seems to be very racey. There now should be a 100ms power-on-to-good delay on all usb 3.0 hubs since 5.4.0-97, which seems like it used to delay whatever race seems to be going on when the roothubs are being registered (as per the discussion here https://bugzilla.kernel.org/show_bug.cgi?id=214021), but maybe that isn't enough to avoid the race in your case? p.s. If you run lsusb -v as root you should be able to see the bPwrOn2PwrGood value of the root hubs as 100ms. Also, the patchset that seemed to directly address this issue got reverted due to regressions and never seemed to be re-addressed upstream... there seem to be a lot of fixes for those introduced problems since then though so maybe it would make sense to reintroduce those patches. I will send an email to the upstream usb mailing list asking about this and see what their thoughts are. Thanks, - Luke ** Bug watch added: Linux Kernel Bug Tracker #214021 https://bugzilla.kernel.org/show_bug.cgi?id=214021 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-intel-5.13 in Ubuntu. https://bugs.launchpad.net/bugs/1939638 Title: [regression] USB device is not detected during boot Status in HWE Next: New Status in linux package in Ubuntu: Fix Released Status in linux-intel package in Ubuntu: Confirmed Status in linux-intel-5.13 package in Ubuntu: Fix Released Status in linux source package in Focal: Fix Released Status in linux-intel source package in Focal: Confirmed Status in linux-intel-5.13 source package in Focal: Fix Released Status in linux source package in Hirsute: Fix Released Status in linux-intel source package in Hirsute: Invalid Status in linux-intel-5.13 source package in Hirsute: Invalid Bug description: [SRU Justification] [Impact] The USB devices (keyboard, storage...) are failed to be detected when connecting to the problematic root hubs which need longer PowerOn-to-PowerGood delay than it claims in the hub descriptor. It's caused by the upstream fix 90d28fb53d4a ("usb: core: reduce power-on-good delay time of root hub"). [Fix] Reverting the upstream fix until a formal fix been placed. [Test Case] 1. Plug the USB device to the ports of problematic root hub. 2. Power on the machine. 3. Check if the USB device can work or not after boot. [Regression Potential] Low. The longer delay is proven safe in old kernels. ========== Original Bug Description ========== [Summary] The USB devices (keyboard, storage...) are failed to be detected during boot after upgrade to UBUNTU focal kernel 5.4.0-78 and hirsute 5.11.0-26. However, they will be detected and working ok after re-plugging. The kernel output shows as down below during boot [ 39.350435] hub 1-0:1.0: USB hub found [ 39.398835] hub 1-0:1.0: 12 ports detected [ 39.622744] usb usb1-port3: couldn't allocate usb_device And when I plug out then plug in the same device, it shows [57210.794140] usb 1-3: new low-speed USB device number 4 using xhci_hcd [57210.951289] usb 1-3: New USB device found, idVendor=17ef, idProduct=6099, bcdDevice= 1.14 [57210.951293] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 After doing kernel bisecting, we found the upstream commit https://github.com/torvalds/linux/commit/90d28fb53d4a51299ff324dede015d5cb11b88a2 makes the difference. It indicates that the delay for the root hub from power_on to power_good is not long enough. There was no problem if the delay is 100 ms. From the Hub Descriptor of the root hub, the value is 10 * 2 milliseconds. And the XHCI spec also says in section 5.4.8 """ The host is required to have power stable to the port within 20 milliseconds of the '0' to '1' transition of PP. If PPC = '1', software is responsible for waiting 20ms. """ The commit seems to follow the SPEC but could cause problems on some hubs. [Reproduce Steps] 1. Plug the USB device to the physical port #1 and #4 which belongs to high-speed hub. 2. Power on the machine. 3. Check if the USB device can work or not after boot. [Results] Expected: All usb devices connect to the hub should work OK. Actual: USB devices connects to high-speed hub can not be probed. [Additional Information] Kernel Version: focal 5.4.0-78 and hirsute 5.11.0-26 [Upstream bug] https://bugzilla.kernel.org/show_bug.cgi?id=214021 To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1939638/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
