Wow Imperia, you're being really helpful here, thank you very much! To enable traces, these are the instructions I've provided to other people affected so far:
0) Reboot the machine in order to put it in a consistent state; 1) echo "module xhci_hcd +flpt" > /sys/kernel/debug/dynamic_debug/control 2) echo nop > /sys/kernel/debug/tracing/current_tracer 3) echo 81920 > /sys/kernel/debug/tracing/buffer_size_kb 4) echo 0 > /sys/kernel/debug/tracing/trace 5) echo 1 > /sys/kernel/debug/tracing/tracing_on 6) echo 1 > /sys/kernel/debug/tracing/events/xhci-hcd/enable After reproduce the issue, you should collect /sys/kernel/debug/tracing/trace. Problem is that the file might be huge, much larger than the kernel log you provided for instance. About the SSH access, I'm interested in getting it next week, if it doesn't annoy you too much. It'll be really helpful, but I might need to reboot the machine. Oh, I've downloaded the logs from your website, so you can delete it now. Cheers, Guilherme -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1749961 Title: xhci_hcd: TRB DMA errors reported with ASMedia ASM1142 USB 3.1 Controller Status in linux package in Ubuntu: In Progress Status in linux source package in Trusty: In Progress Status in linux source package in Xenial: In Progress Status in linux source package in Artful: In Progress Status in linux source package in Bionic: In Progress Status in linux package in Debian: New Bug description: It was observed that while trying to use a 4K USB webcam connected to USB port provided by ASMedia ASM1142 USB 3.1 Controller, the webcam does not work and kernel log shows the following messages: [431.928016] xhci_hcd 0000:12:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13 [431.928021] xhci_hcd 0000:12:00.0: Looking for event-dma 0000003f3330e020 trb-start 0000003f3330e000 trb-end 0000003f3330e000 seg-start 0000003f3330e000 seg-end 0000003f3330eff0 [431.928024] xhci_hcd 0000:12:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13 [431.928026] xhci_hcd 0000:12:00.0: Looking for event-dma 0000003f3330e030 trb-start 0000003f3330e000 trb-end 0000003f3330e000 seg-start 0000003f3330e000 seg-end 0000003f3330eff0 [431.928027] xhci_hcd 0000:12:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13 [431.928029] xhci_hcd 0000:12:00.0: Looking for event-dma 0000003f3330e050 trb-start 0000003f3330e000 trb-end 0000003f3330e000 seg-start 0000003f3330e000 seg-end 0000003f3330eff0 [431.928386] xhci_hcd 0000:12:00.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2 comp_code 13 A similar issue was already reported on Launchpad: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1667750 The fix to this issue seems to be the following patch: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9da5a109 Tests in our scenario with this patch proved still broken. Our next approach is to modify the patch a bit and re-test. This LP will be used to document our progress in the investigation. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1749961/+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
