=================
dmesg
=================

... nothing for hours before ...
[23390.544400] ohci-pci 0000:00:13.1: OHCI SF watchdog triggered
[23390.544411] ohci-pci 0000:00:13.1: Frame counter has stopped at 49248
[23390.544415] ohci-pci 0000:00:13.1: Disabling OHCI controller
[23390.544419] ohci-pci 0000:00:13.1: HC died; cleaning up
[23390.544552] usb 3-3: USB disconnect, device number 3
[23392.973038] irq 19: nobody cared (try booting with the "irqpoll" option)
[23392.973050] CPU: 0 PID: 0 Comm: swapper Tainted: G           O 3.14.0-rc3 #7
[23392.973054] Hardware name: Acer, inc. Ferrari 4000    /Ferrari IV      , BIOS 3A23 10/24/05
[23392.973058]  ffff88004df74a58 ffffffff81c21e38 ffffffff81618bad ffffffff81c21e58
[23392.973065]  ffffffff81070274 ffff88004df74a00 0000000000000013 ffffffff81c21ea8
[23392.973072]  ffffffff8107053f 0000000000000013 ffff88004d447c00 0000000000000000
[23392.973078] Call Trace:
[23392.973081]  <IRQ>  [<ffffffff81618bad>] dump_stack+0x19/0x1b
[23392.973100]  [<ffffffff81070274>] __report_bad_irq.isra.7+0x24/0xd0
[23392.973106]  [<ffffffff8107053f>] note_interrupt+0x1af/0x200
[23392.973115]  [<ffffffff8106e659>] handle_irq_event_percpu+0x89/0x160
[23392.973122]  [<ffffffff8105c195>] ? sched_clock_local.constprop.5+0x15/0x80
[23392.973129]  [<ffffffff8106e770>] handle_irq_event+0x40/0x70
[23392.973137]  [<ffffffff8107ef6e>] ? tick_nohz_stop_idle.constprop.27+0x2e/0x40
[23392.973143]  [<ffffffff810710a0>] handle_fasteoi_irq+0x50/0x110
[23392.973149]  [<ffffffff81003e6d>] handle_irq+0x1d/0x30
[23392.973154]  [<ffffffff81003c46>] do_IRQ+0x56/0x100
[23392.973162]  [<ffffffff8161ebe8>] common_interrupt+0x68/0x68
[23392.973164]  <EOI>  [<ffffffff81475cdc>] ? cpuidle_enter_state+0x4c/0xd0
[23392.973177]  [<ffffffff81475cd8>] ? cpuidle_enter_state+0x48/0xd0
[23392.973184]  [<ffffffff81475df6>] cpuidle_idle_call+0x96/0x130
[23392.973192]  [<ffffffff8100ab19>] arch_cpu_idle+0x9/0x20
[23392.973199]  [<ffffffff8106dd0a>] cpu_startup_entry+0x7a/0x160
[23392.973206]  [<ffffffff8161289a>] rest_init+0x7a/0x80
[23392.973213]  [<ffffffff81c87d58>] start_kernel+0x2e6/0x2f3
[23392.973219]  [<ffffffff81c87871>] ? repair_env_string+0x5e/0x5e
[23392.973225]  [<ffffffff81c875a5>] x86_64_start_reservations+0x2a/0x2c
[23392.973231]  [<ffffffff81c87670>] x86_64_start_kernel+0xc9/0xcd
[23392.973238]  [<ffffffff81024a40>] ? x86_acpi_suspend_lowlevel+0xd0/0xd0
[23392.973240] handlers:
[23392.973247] [<ffffffff813fe7c0>] usb_hcd_irq
[23392.973252] [<ffffffff813fe7c0>] usb_hcd_irq
[23392.973258] [<ffffffff813fe7c0>] usb_hcd_irq
[23392.973260] Disabling IRQ #19


=================
stuff in /sys/kernel/debug/usb/ohci
hcca frame counter stopped, and so did the "fmremaining ... fr" values, unlike last time. last time, there was also a "FRT" tag on that line, unlike this time.
=================

==> async <==

==> periodic <==
size = 32
 0 [179]: ed1/ffff88004701a000 (fs dev3 ep1in-int qlen 1 max 16 00101083) ed1/ffff88004701a0a0 (fs dev3 ep3out-iso qlen 15 max 192 00c08983)
 1 [179]: ed1/ffff88004701a000
 2 [179]: ed1/ffff88004701a000
 3 [179]: ed1/ffff88004701a000
 4 [179]: ed1/ffff88004701a000
 5 [179]: ed1/ffff88004701a000
 6 [179]: ed1/ffff88004701a000
 7 [179]: ed1/ffff88004701a000
 8 [179]: ed1/ffff88004701a000
 9 [179]: ed1/ffff88004701a000
10 [179]: ed1/ffff88004701a000
11 [179]: ed1/ffff88004701a000
12 [179]: ed1/ffff88004701a000
13 [179]: ed1/ffff88004701a000
14 [179]: ed1/ffff88004701a000
15 [179]: ed1/ffff88004701a000
16 [179]: ed1/ffff88004701a000
17 [179]: ed1/ffff88004701a000
18 [179]: ed1/ffff88004701a000
19 [179]: ed1/ffff88004701a000
20 [179]: ed1/ffff88004701a000
21 [179]: ed1/ffff88004701a000
22 [179]: ed1/ffff88004701a000
23 [179]: ed1/ffff88004701a000
24 [179]: ed1/ffff88004701a000
25 [179]: ed1/ffff88004701a000
26 [179]: ed1/ffff88004701a000
27 [179]: ed1/ffff88004701a000
28 [179]: ed1/ffff88004701a000
29 [179]: ed1/ffff88004701a000
30 [179]: ed1/ffff88004701a000
31 [179]: ed1/ffff88004701a000

==> registers <==
bus pci, device 0000:00:13.1
OHCI PCI host controller
ohci_hcd
OHCI 1.0, NO legacy support registers, rh state halted
control 0x200 RWC HCFS=reset CBSR=0
cmdstatus 0x10002 SOC=1 CLF
intrstatus 0x00000061 RHSC FNO SO
intrenable 0x8000005e MIE RHSC UE RD SF WDH
ed_periodcurrent 4701a0a0
ed_controlhead 4701a050
donehead 00e3fb40
hcca frame 0xc060
fmintvl 0x27782edf FSMPS=0x2778 FI=0x2edf
fmremaining 0x00002857 FR=0x2857
periodicstart 0x2a2f
lsthresh 0x0628
hub poll timer off
roothub.a 02000204 POTPGT=2 NPS NDP=4(4)
roothub.b 00000000 PPCM=0000 DR=0000
roothub.status 00000000
roothub.portstatus [0] 0x00000100 PPS
roothub.portstatus [1] 0x00000100 PPS
roothub.portstatus [2] 0x00000100 PPS
roothub.portstatus [3] 0x00000100 PPS