Re: Problem: irq 217: nobody cared + backtrace

From: Jesper Juhl
Date: Fri Aug 04 2006 - 18:38:30 EST


On 04/08/06, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
On Fri, 4 Aug 2006, Jesper Juhl wrote:

> On 03/08/06, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > Has this happened more than once?
>
> Seems to happen consistently after ~100000 interrupts.
>
> > In case it happens again, here's how
> > you can get more information. Turn on CONFIG_USB_DEBUG and
> > CONFIG_DEBUG_FS, and mount a debugfs filesystem somewhere (say
> > /sys/kernel/debug). Then after the problem occurs, save a copy of
> >
> > /sys/kernel/debug/uhci/0000:00:1d.1
> >
>
> # cat /sys/kernel/debug/uhci/0000:00:1d.1
> Root-hub state: auto-stopped FSBR: 0
> HC status
> usbcmd = 0048 Maxp32 CF EGSM
> usbstat = 0020 HCHalted
> usbint = 0002
> usbfrnum = (1)160
> flbaseadd = 37428160
> sof = 40
> stat1 = 0080
> stat2 = 0080
> Most recent frame: 458 (88) Last ISO frame: 458 (88)
>
>
> > That will indicate whether the UHCI controller thinks it is sending an
> > interrupt request.

And it shows that the controller is idle. No IRQ should be pending.

> And just for completenes, here's the backtrace I got just before
> saving the above info :
>
> irq 217: nobody cared (try booting with the "irqpoll" option)
> [<c0103a3c>] show_trace_log_lvl+0x152/0x165
> [<c0103a5e>] show_trace+0xf/0x13
> [<c0103b59>] dump_stack+0x15/0x19
> [<c013846e>] __report_bad_irq+0x24/0x7f
> [<c0138552>] note_interrupt+0x6b/0xd5
> [<c0137ca8>] __do_IRQ+0xf4/0x100
> [<c01050a1>] do_IRQ+0x95/0xbc
> [<c0103502>] common_interrupt+0x1a/0x20
> [<c0137b7e>] handle_IRQ_event+0x20/0x56
> [<c0137c4c>] __do_IRQ+0x98/0x100
> [<c01050a1>] do_IRQ+0x95/0xbc
> [<c0103502>] common_interrupt+0x1a/0x20
> [<c0100e64>] mwait_idle+0x30/0x35
> [<c0100d45>] cpu_idle+0x78/0x81
> [<c04cc7fb>] start_kernel+0x173/0x19d
> [<c0100210>] 0xc0100210
> DWARF2 unwinder stuck at 0xc0100210
> Leftover inexact backtrace:
> =======================
> handlers:
> [<c02c5c22>] (usb_hcd_irq+0x0/0x53)
> Disabling IRQ #217

Just as before.

I can't tell you what's causing this to happen, except that it appears to
be some sort of hardware problem.

Hmm, the odd thing is that there are no USB devices connected at all.


Since it doesn't seem to cause any harm
you could just live with it.

Or, if you're not using any full-speed or low-speed USB devices, you could
simply prevent uhci-hcd from loading at all. Then IRQ 217 wouldn't get
enabled in the first place.

True, that just seems like a hack...


--
Jesper Juhl <jesper.juhl@xxxxxxxxx>
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