Re: [REGRESSION] usbhid -110 timeouts and reset loop for Keychron M5 (3434:d068) at boot since v7.3

[Dennis Wissel <dennis@dsine.de>]

On Sun, 25 Oct 2026 11:14:10 +0100, Michal Pecio wrote:
> This could result in DMAR faults, but it didn't. Was IOMMU enabled?

No. The kernel command line has no intel_iommu=on,
CONFIG_INTEL_IOMMU_DEFAULT_ON is not set, and /sys/class/iommu is
empty. DMAR is only used for interrupt remapping. I won't boot
7.3+1f36cc9fa949 again. The box now runs 7.3 with 042aad8d0db6 and
7e0ef4332ed9 reverted.

> But can you post what happens on 7.2 with xhci_hcd and usbcore
> dynamic debug enabled?

7.2.11-1-cachyos booted with "xhci_hcd.dyndbg=+p usbcore.dyndbg=+p
log_buf_len=16M", mouse plugged in at boot. Below are the lines for
port 1-1 / slot 1. The full log is 270 KB, so I can send it off-list or
post it somewhere if needed.

This time all four interfaces failed with -71, not only 2 and 3 as
in my earlier 7.2.11 boots, and there was no "usb 1-1: reset", only
the disconnect/re-enumeration. The device seems to drop off the bus
right after Set Configuration, at the first control transfer of the
usbhid probe:

[    3.537963] xhci_hcd 0000:00:14.0: set port reset, actual port 1-1 status  = 0x791
[    3.538304] usb 1-1: new full-speed USB device number 2 using xhci_hcd
[    3.538344] xhci_hcd 0000:00:14.0: Slot ID 1: HW portnum 0, hcd portnum 0
[    3.540254] usb 1-1: ep0 maxpacket = 8
[    3.540543] usb 1-1: New USB device found, idVendor=3434, idProduct=d068, bcdDevice= 1.00
[    3.541469] usb 1-1: configuration #1 chosen from 1 choice
[    3.541509] xhci_hcd 0000:00:14.0: add ep 0x82, slot id 1, new drop flags = 0x0, new add flags = 0x21
[    3.541673] xhci_hcd 0000:00:14.0: add ep 0x83, slot id 1, new drop flags = 0x0, new add flags = 0x6a9
[    3.542427] usb 1-1: adding 1-1:1.0 (config #1, interface 0)
[    3.542477] usbhid 1-1:1.0: usb_probe_interface
[    3.542526] usbhid 1-1:1.0: usb_probe_interface - got id
[    3.542566] xhci_hcd 0000:00:14.0: Transfer error for slot 1 ep 0 on endpoint
[    3.542606] xhci_hcd 0000:00:14.0: TRB error 4, halted endpoint index = 0
[    3.542646] xhci_hcd 0000:00:14.0: Hard-reset ep 0, slot 1
[    3.542725] xhci_hcd 0000:00:14.0: Ignoring reset ep completion code of 1
[    3.542923] xhci_hcd 0000:00:14.0: Port change event, 1-1, id 1, portsc: 0x202a0
[    3.543163] xhci_hcd 0000:00:14.0: Transfer error for slot 1 ep 0 on endpoint
[    3.543203] xhci_hcd 0000:00:14.0: TRB error 4, halted endpoint index = 0
[    3.543244] xhci_hcd 0000:00:14.0: Hard-reset ep 0, slot 1
[    3.543326] xhci_hcd 0000:00:14.0: Ignoring reset ep completion code of 1
  [... the same 4 lines for each further control transfer, about
       every 0.5 ms ...]
[    3.544720] usbhid 1-1:1.0: can't add hid device: -71
[    3.544804] usb 1-1: adding 1-1:1.1 (config #1, interface 1)
[    3.547532] usbhid 1-1:1.1: can't add hid device: -71
[    3.547617] usb 1-1: adding 1-1:1.2 (config #1, interface 2)
[    3.550329] usbhid 1-1:1.2: can't add hid device: -71
[    3.550413] usb 1-1: adding 1-1:1.3 (config #1, interface 3)
[    3.553190] usbhid 1-1:1.3: can't add hid device: -71
  [... hub_wq enumerates the other ports, nothing for 1-1 ...]
[    5.065514] hub 1-0:1.0: state 7 ports 16 chg 0000 evt 0002
[    5.065577] xhci_hcd 0000:00:14.0: Get port status 1-1 read: 0x206e1, return 0x10101
[    5.065637] xhci_hcd 0000:00:14.0: clear port1 connect change, portsc: 0x6e1
[    5.065692] usb usb1-port1: status 0101, change 0001, 12 Mb/s
[    5.065697] usb 1-1: USB disconnect, device number 2
[    5.065750] usb 1-1: usb_disable_device nuking all URBs
[    5.065810] xhci_hcd 0000:00:14.0: drop ep 0x81, slot id 1, new drop flags = 0x8, new add flags = 0x0
[    5.066201] xhci_hcd 0000:00:14.0: drop ep 0x5, slot id 1, new drop flags = 0x6a8, new add flags = 0x0
[    5.170113] usb usb1-port1: debounce total 100ms stable 100ms status 0x101
[    5.354755] xhci_hcd 0000:00:14.0: set port reset, actual port 1-1 status  = 0x791
[    5.466345] usb 1-1: new full-speed USB device number 11 using xhci_hcd
[    5.597007] hid-generic 0003:3434:D068.0009: input,hidraw8: USB HID v1.11 Mouse [Keychron Keychron M5 ] on usb-0000:00:14.0-1/input0
[    5.684004] hid-generic 0003:3434:D068.000A: input,hidraw9: USB HID v1.11 Keyboard [Keychron Keychron M5 ] on usb-0000:00:14.0-1/input1
[    5.685139] hid-generic 0003:3434:D068.000B: hiddev100,hidraw10: USB HID v1.11 Device [Keychron Keychron M5 ] on usb-0000:00:14.0-1/input2
[    5.686139] hid-generic 0003:3434:D068.000C: hiddev101,hidraw11: USB HID v1.11 Device [Keychron Keychron M5 ] on usb-0000:00:14.0-1/input3

So on 7.2 the disconnect (portsc 0x202a0, CCS=0) is reported at
3.542923, and the device is connected again (0x206e1) by the time
hub_wq looks at port 1 at 5.065. There is no other port change event
for 1-1 in between. All ep0 transfers to the gone device fail within
about 0.5 ms with a transaction error, so the probes are done after
11 ms.

Regards, Dennis