Re: [Bug #14487] PANIC: early exception 08 rip 246:10 error ffffffff810251b5 cr2 0

Dan Carpenter
2010-02-01T12:54:41Z

On Sun, Jan 31, 2010 at 05:39:22PM -0800, Justin P. Mattock wrote:
> On 01/31/10 16:43, Rafael J. Wysocki wrote:
>> This message has been generated automatically as a part of a report
>> of regressions introduced between 2.6.31 and 2.6.32.
>>
>> The following bug entry is on the current list of known regressions
>> introduced between 2.6.31 and 2.6.32. Please verify if it still should
>> be listed and let me know (either way).
>>
>>
>> Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=14487
>> Subject : PANIC: early exception 08 rip 246:10 error ffffffff810251b5 cr2 0
>> Submitter : Justin P. Mattock<justinmattock-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> Date : 2009-10-23 16:45 (101 days old)
>> References : http://lkml.org/lkml/2009/10/23/252
>>
>>
>>
>
>
> yeah still hitting this.
> looking at the issue if I change:
>
> @@ 260
>
> if ((class == 0xffffffff))
> continue;
> to
>
> if ((class == 0xffffffff || 0xffffffffffffffff))
> continue;
>

Uh... 0xffffffffffffffff is always true so basically that's the same as deleting the
if condition.

I've added the linux1394-devel people to the CC list.

Justin has found an issue that when he boots with: ohci1394_dma=early his computer
crashes.

He can get it to boot by modifying drivers/ieee1394/init_ohci1394_dma.c:

init_ohci1394_dma_on_all_controllers()
254 /* Poor man's PCI discovery, the only thing we can do at early boot */
255 for (num = 0; num < 32; num++) {
256 for (slot = 0; slot < 32; slot++) {
257 for (func = 0; func < 8; func++) {
258 u32 class = read_pci_config(num,slot,func,
259 PCI_CLASS_REVISION);
260 if ((class == 0xffffffff))
261 continue; /* No device at this func */

If he continues here then his system boots.

262
263 if (class>>8 != PCI_CLASS_SERIAL_FIREWIRE_OHCI)
264 continue; /* Not an OHCI-1394 device */
265
266 init_ohci1394_controller(num, slot, func);
267 break; /* Assume one controller per device */

This comment is not terribly clear btw. The code assumes one controller per slot.

268 }
269 }
270 }

regards,
dan carpenter

> I'm able to boot, but don't have enough knowledge to know
> what is really happening(or how to execute this).
> will continue looking at this
> (hopefully I get somewhere on this);
>
> Justin P. Mattock
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/