[linux-dvb] CX88 IRQ Loop

Darren Salt linux at youmustbejoking.demon.co.uk
Tue Sep 23 00:38:31 CEST 2008

I demand that Timothy E. Krantz may or may not have written...

> I am getting the following problems as reported in dmesg.
> Any help would be appreciated.

> Linux video capture interface: v2.00
> cx2388x alsa driver version 0.0.6 loaded
> ACPI: PCI Interrupt 0000:00:09.1[A] -> GSI 17 (level, low) -> IRQ 20
> cx88[0]: subsystem: 11bd:0051, board: Pinnacle PCTV HD 800i
> xc5000: firmware upload
> NVRM: loading NVIDIA UNIX x86 Kernel Module  169.12  Thu Feb 14 17:53:07 PST 2008
> ndiswrapper version 1.51 loaded (smp=yes, preempt=no)
> usb 1-5: reset high speed USB device using ehci_hcd and address 2
> ndiswrapper: driver netmw245 (Marvell,11/27/2006, loaded
> cx88[0]/2-mpeg: general errors: 0x00140000
> cx88[0]/2-mpeg: clearing mask
> cx88[0]/0: irq loop -- clearing mask
> cx88[0]: irq mpeg  [0xa0000] par_err* pci_abort*
> cx88[0]/2-mpeg: general errors: 0x000a0000
> irq 20: nobody cared (try booting with the "irqpoll" option)
> Pid: 0, comm: swapper Tainted: P #1
>  [<c04612be>] __report_bad_irq+0x36/0x75
>  [<f15a3a16>] nv_kern_isr+0xa5/0xb2 [nvidia]

Oh dear. I do believe that that's within nVidia's proprietary driver.

And you're using ndiswrapper, and it's loaded a driver module. That's another
source of kernel taint. This raises the possibility of some interaction
between the two, which basically You Don't Want To See. Ever.

Which isn't good because one or other, or some interaction between them, is a
possible source of the problem. So you need to be able to produce this
without one or both taint sources: without one, it's likely caused by the
other piece of taintware; without both, you know that the problem isn't
caused by taintware (it's either a cx88 driver bug or a hardware fault). If,
however, it only ever happens with both lots of taint applied, you have a
problem somewhere between nVidia and either ndiswrapper or netwm245 – good
luck ;-)

(Taint removal: prevent the taintware from being loaded, then reboot.)

| Darren Salt    | linux or ds at              | nr. Ashington, | Toon
| RISC OS, Linux | youmustbejoking,demon,co,uk | Northumberland | Army
| + At least 4000 million too many people. POPULATION LEVEL IS UNSUSTAINABLE.

Hire the morally handicapped.

More information about the linux-dvb mailing list