USB hub on Thunderbolt-connected monitor broken on MacBookPro18,4 (M1 Max) since 6.18.x #458
Description
Since upgrading to 6.18.10-402, the internal USB hub in my monitor (connected via USB-C) no longer works. Devices plugged directly into the Mac via USB-C work fine — for example, a DualSense controller shows up in lsusb. But anything connected through the monitor's hub is not detected at all.
In dmesg I see all three Thunderbolt USB controllers failing to initialize:
xhci-hcd xhci-hcd.1.auto: probe with driver xhci-hcd failed with error -22
xhci-hcd xhci-hcd.2.auto: probe with driver xhci-hcd failed with error -22
xhci-hcd xhci-hcd.3.auto: probe with driver xhci-hcd failed with error -22
Booting 6.17.9-400 fixes it.
U-boot shows the expected number of USB connections, but none work after that stage
Machine: MacBookPro18,4 (M1 Max 14")
Broken: 6.18.10-402.asahi.fc42.aarch64+16k
Working: 6.17.9-400.asahi.fc42.aarch64+16k
Distro: Fedora Asahi Remix
Monitor: LG27UP850-W