[CC stable as I only tested the stable tree for now] I'm running a current Alpine Linux with linux-edge-6.1.8-r0 installed on a Lenovo Thinkpad L540 where an external disk enclosure with two disks is attached via USB. The Alpine Linux kernel appears to track Linux stable and is more or less vanilla. Also, the machine boots into Xen 4.17.0 and then starts a few headless VMs, nothing too exotic here. But when updating from Linux 6.1.1 to 6.1.8, the disks from the external enclosure did not show up. Unplug, replug, no dice, and this is 100% reproducable. dmesg has new these lines now: +ioremap error for 0xf2520000-0xf2530000, requested 0x2, got 0x0 +ioremap error for 0xf2520000-0xf2530000, requested 0x2, got 0x0 +xhci_hcd 0000:00:14.0: init 0000:00:14.0 fail, -14 +ioremap error for 0xfed1f000-0xfed20000, requested 0x2, got 0x0 +iTCO_wdt iTCO_wdt.1.auto: ioremap failed for resource [mem 0xfed1f410-0xfed1f414] I'm not sure if the ioremap error is related here (booted with early_ioremap_debug but then dmesg was filled with WARNINGS for both versions, so I disabled it again), but that xhci_hcd error looks suspicious. Curiously 6.1.8 works just fine when NOT booted via Xen. I booted into Xen + vanilla 6.1.8 now and was able to reproduce this issue. Xen + vanilla 6.1.1 works fine. >From v6.1.1 to v6.1.8 there's only one commit in drivers/xen, but 54 commits in drivers/usb. Compiling takes time because the distribution kernel has almost everything enabled and I still need to cut down enabled options to be able to attempt a git biset in a reasonable time, but I still wanted to report this, maybe someone has an idea about this. Full dmesg and lshw outputs: https://nerdbynature.de/bits/usb_v6.1.8/ Thanks, Christian. PS: I found this workaround on the interwebs[0] to force the USB ports of that machine to USB 2.0 and then the missing disks magically appear: $ lspci -nn | grep -i usb 00:14.0 USB controller [0c03]: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI [8086:8c31] (rev 05) <=== !!! 00:1a.0 USB controller [0c03]: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #2 [8086:8c2d] (rev 05) 00:1d.0 USB controller [0c03]: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #1 [8086:8c26] (rev 05) $ setpci -H1 -d 8086:8c31 d8.l=0 $ setpci -H1 -d 8086:8c31 d0.l=0 $ dmesg usb 1-1.3: new full-speed USB device number 3 using ehci-pci usb 2-1.3: new high-speed USB device number 3 using ehci-pci usb 1-1.3: New USB device found, idVendor=138a, idProduct=0011, bcdDevice=0.78 usb 1-1.3: New USB device strings: Mfr=0, Product=0, SerialNumber=1 usb 1-1.3: SerialNumber: aa32bf84ed47 usb 1-1.5: new full-speed USB device number 4 using ehci-pci usb 2-1.3: New USB device found, idVendor=1e91, idProduct=a3a8, bcdDevice=2.07 usb 2-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=5 usb 2-1.3: Product: Elite Pro Dual usb 2-1.3: Manufacturer: OWC usb 2-1.3: SerialNumber: RANDOM__1E359879645F usb 2-1.3: UAS is ignored for this device, using usb-storage instead usb-storage 2-1.3:1.0: USB Mass Storage device detected usb-storage 2-1.3:1.0: Quirks match for vid 1e91 pid a3a8: 800000 scsi host5: usb-storage 2-1.3:1.0 usb 1-1.5: New USB device found, idVendor=8087, idProduct=07dc, bcdDevice=0.01 usb 1-1.5: New USB device strings: Mfr=0, Product=0, SerialNumber=0 Bluetooth: hci0: Legacy ROM 2.5 revision 8.0 build 1 week 45 2013 Bluetooth: hci0: Intel Bluetooth firmware file: intel/ibt-hw-37.7.10-fw-1.80.1.2d.d.bseq usb 1-1.6: new high-speed USB device number 5 using ehci-pci usb 1-1.6: New USB device found, idVendor=04f2, idProduct=b398, bcdDevice=39.98 usb 1-1.6: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 1-1.6: Product: Integrated Camera usb 1-1.6: Manufacturer: Vimicro corp. Bluetooth: hci0: Intel BT fw patch 0x2a completed & activated scsi 5:0:0:0: Direct-Access ElitePro Dual U3FW-1 0207 PQ: 0 ANSI: 6 scsi 5:0:0:1: Direct-Access ElitePro Dual U3FW-2 0207 PQ: 0 ANSI: 6 sd 5:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16). sd 5:0:0:0: [sdc] 7814037168 512-byte logical blocks: (4.00 TB/3.64 TiB) sd 5:0:0:1: [sdd] Very big device. Trying to use READ CAPACITY(16). sd 5:0:0:1: [sdd] 7814037168 512-byte logical blocks: (4.00 TB/3.64 TiB) sd 5:0:0:1: [sdd] Write Protect is off sd 5:0:0:1: [sdd] Mode Sense: 47 00 10 08 sd 5:0:0:0: [sdc] Write Protect is off sd 5:0:0:0: [sdc] Mode Sense: 47 00 10 08 sd 5:0:0:0: [sdc] No Caching mode page found sd 5:0:0:0: [sdc] Assuming drive cache: write through sd 5:0:0:1: [sdd] No Caching mode page found sd 5:0:0:1: [sdd] Assuming drive cache: write through sd 5:0:0:0: [sdc] Attached SCSI disk sd 5:0:0:1: [sdd] Attached SCSI disk $ lsblk /dev/sd[cd] NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS sdc 8:32 0 3.6T 0 disk sdd 8:48 0 3.6T 0 disk [0] https://superuser.com/a/875863/218574 -- BOFH excuse #135: You put the disk in upside down.