USB-related panic in 8.2_STABLE

[Timo Buhrmester <timo%math.uni-bonn.de@localhost>]

Apparently out of nothing, one of our servers paniced.


uname -a gives:

| NetBSD trave.math.uni-bonn.de 8.2_STABLE NetBSD 8.2_STABLE (MI-Server) #17: Fri Jul 16 14:01:03 CEST 2021  support%trave.math.uni-bonn.de@localhost:/var/work/obj-8/sys/arch/amd64/compile/miserv amd64

I've transcribed the panic message and backtrace:

| ohci0: 1 scheduling overruns
| ugen0: detached
| ugen0: at uhub4 port 2 (addr 2) disconnected
| ugen0 at uhub4 port 2
| ugen0: Phoenixtec Power (0x6da) USB Cable (V2.00) (0x02), rev 1.00/0.06, addr 2
| uvm_fault(0xfffffe82574c2458, 0x0, 1) -> e
| fatal page fault in supervisor mode
| trap type 6 code 0 rip 0xffffffff802f627e cs 0x8 rflags 0x10246 cr2 0x2 ilevel 6 (NB: could be ilevel 0 as well) rsp 0xffff80013f482c10
| curlwp 0xfffffe83002b2000 pid 8393.1 lowest kstack 0xffff80013f4802c0
| kernel: page fault trap, code=0
| Stopped in pid 8393.1 (nutdrv_qx_usb) at       netbsd:ugen_get_cdesc+0xb1:
| movzwl 2(%rax),%edx
| db{2}> bt
| ugen_get_cdesc() at netbsd:ugen_get_cdesc+0xb1
| ugenioctl() at netbsd:ugenioctl+0x9a4
| cdev_ioctl() at netbsd:cdev_ioctl+0xb4
| VOP_IOCTL() at netbsd:VOP_IOCTL+0x54
| vn_ioctl() at netbsd:vn_ioctl+0xa6
| sys_ioctl() at netbsd:sys_ioctl+0x11a
| syscall() at netbsd:syscall+0x1ec
| --- syscall (number 54) ---
| 7a73c9eff13a:
| db{2}>

Any idea what's going on?

Cheers
Timo Buhrmester