netbsd-9 sys/dev/usb/ehci.c panic: exfer->ex_isdone

[Paul Ripke <stix%stix.id.au@localhost>]

I've had a couple of recent crashes on amd64, likely due to a dodgy USB
hub. Still, no matter how bad the hub is, I think the crashes indicate a
bug somewhere.

System is:
NetBSD slave 9.1_STABLE NetBSD 9.1_STABLE (SLAVE) #5: Wed Dec  9 17:19:04 AEDT 2020  stix@slave:/home/netbsd/netbsd-9/obj.amd64/home/netbsd/netbsd-9/src/sys/arch/amd64/compile/SLAVE amd64

I updated between the two crashes to see if there'd been any relevant
updates.

USB tree is usually something like:
ksh$ sudo usbdevs
addr 1: EHCI root hub, NetBSD
 addr 2: Rate Matching Hub, Intel
  addr 3: USB 2.0 Hub, Terminus Technology
   addr 4: Gaming KB, Gaming KB
   addr 5: Microsoft Basic Optical Mouse v2.0, Microsoft
   addr 6: product 0042, Arduino (www.arduino.cc)
  addr 7: Ext HDD 1021, Western Digital
addr 1: EHCI root hub, NetBSD
 addr 2: Rate Matching Hub, Intel
  addr 4: MT1806, MediaTek Inc
  addr 5: Bluetooth USB Adapter, Cambridge Silicon Radio

Dec  7 11:43:56 slave /netbsd: [ 3150526.7715654] panic: kernel diagnostic assertion "exfer->ex_isdone" failed: file "/home/netbsd/netbsd-9/src/sys/dev/usb/ehci.c", line 4079 
Dec  7 11:43:56 slave /netbsd: [ 3150526.7715654] cpu0: Begin traceback...
Dec  7 11:43:56 slave /netbsd: [ 3150526.7715654] vpanic() at netbsd:vpanic+0x160
Dec  7 11:43:56 slave /netbsd: [ 3150526.7715654] stge_eeprom_wait.isra.4() at netbsd:stge_eeprom_wait.isra.4
Dec  7 11:43:56 slave /netbsd: [ 3150526.7715654] ehci_device_intr_start() at netbsd:ehci_device_intr_start+0x275
Dec  7 11:43:56 slave /netbsd: [ 3150526.7715654] usbd_start_next() at netbsd:usbd_start_next+0xd6
Dec  7 11:43:56 slave /netbsd: [ 3150526.7715654] ehci_abortx() at netbsd:ehci_abortx+0x9c
Dec  7 11:43:56 slave /netbsd: [ 3150526.7715654] usbd_xfer_timeout_task() at netbsd:usbd_xfer_timeout_task+0x5c
Dec  7 11:43:56 slave /netbsd: [ 3150526.7815697] usb_task_thread() at netbsd:usb_task_thread+0xba
Dec  7 11:43:56 slave /netbsd: [ 3150526.7815697] cpu0: End traceback...
Dec  7 11:43:56 slave /netbsd: [ 3150526.7815697] uvm_fault(0xfffff566d3edb5c8, 0x0, 1) -> e
Dec  7 11:43:56 slave /netbsd: [ 3150526.7815697] fatal page fault in supervisor mode
Dec  7 11:43:56 slave /netbsd: [ 3150526.7815697] trap type 6 code 0 rip 0xffffffff809c93b2 cs 0x8 rflags 0x10202 cr2 0xa5 ilevel 0x8 rsp 0xffffd1813f40fe30
Dec  7 11:43:56 slave /netbsd: 
Dec  7 11:43:56 slave /netbsd: [ 3150526.7815697] curlwp 0xfffff569ccad1b20 pid 24376.1 lowest kstack 0xffffd1813fd4umpci2ncg 0t

Jan  4 21:43:38 slave /netbsd: [ 2241344.6177737] panic: kernel diagnostic assertion "exfer->ex_isdone" failed: file "/home/netbsd/netbsd-9/src/sys/dev/usb/ehci.c", line 4079 
Jan  4 21:43:38 slave /netbsd: [ 2241344.6177737] cpu0: Begin traceback...
Jan  4 21:43:38 slave /netbsd: [ 2241344.6177737] vpanic() at netbsd:vpanic+0x160
Jan  4 21:43:38 slave /netbsd: [ 2241344.6177737] stge_eeprom_wait.isra.4() at netbsd:stge_eeprom_wait.isra.4
Jan  4 21:43:38 slave /netbsd: [ 2241344.6177737] ehci_device_intr_start() at netbsd:ehci_device_intr_start+0x275
Jan  4 21:43:38 slave /netbsd: [ 2241344.6177737] usbd_start_next() at netbsd:usbd_start_next+0xd6
Jan  4 21:43:38 slave /netbsd: [ 2241344.6177737] ehci_abortx() at netbsd:ehci_abortx+0x9c
Jan  4 21:43:38 slave /netbsd: [ 2241344.6277777] usbd_xfer_timeout_task() at netbsd:usbd_xfer_timeout_task+0x5c
Jan  4 21:43:38 slave /netbsd: [ 2241344.6277777] usb_task_thread() at netbsd:usb_task_thread+0xba
Jan  4 21:43:38 slave /netbsd: [ 2241344.6277777] cpu0: End traceback...
Jan  4 21:43:38 slave /netbsd: [ 2241344.6277777] uvm_fault(0xfffffa8b73c275f0, 0x0, 2) -> e
Jan  4 21:43:38 slave /netbsd: [ 2241344.6277777] fatal page fault in supervisor mode
Jan  4 21:43:38 slave /netbsd: [ 2241344.6277777] trap type 6 code 0x2 rip 0xffffffff809c2626 cs 0x8 rflags 0x10282 cr2 0x84 ilevel 0x8 rsp 0xffffcf817e00cb60
Jan  4 21:43:38 slave /netbsd: 
Jan  4 21:43:38 slave /netbsd: [ 2241344.6277777] curlwp 0xfffffa8b1d6a7500 pid 10543.31 lowest kstack 0xdffufmfpcifn8g1 7teo0 0d9e2vc 0

-- 
Paul Ripke
"Great minds discuss ideas, average minds discuss events, small minds
 discuss people."
-- Disputed: Often attributed to Eleanor Roosevelt. 1948.