kernel panic with firewire PCI card

Andreas Tobler andreast-list at fgznet.ch
Mon Mar 30 12:49:31 PDT 2009


Marius Strobl wrote:
> On Sun, Mar 29, 2009 at 08:15:34PM +0200, Andreas Tobler wrote:
>> Marius Strobl wrote:
>>> PCI AFSR 0x4000000000000000 indicates that the primary error
>>> was a target abort. Given that no DMA is involved at this stage
>>> this means it actually was the OHCI chip which complained
>>> about the PIO access. If this is the first access after the
>>> reset (check with "l *(0xc0659be4)", "l *(fwphy_rddata+0xe8)"
>>> and "l *(fwohci_reset+0x298)" in gdb on the corresponding
>>> kernel.debug what code is actually involved) I'd suspect
>>> the problem to be a combination of a sloppy driver with a
>>> chip that takes some more time than the other contenders
>>> to get ready again after a reset, i.e. fwohci_reset() only
>>> tries 100 times with waiting one millisecond between tries
>>> for OHCI_HCC_RESET to clear after the reset (the latter part
>>> is in line with the OHCI specification). Increasing to f.e.
>>> 1000 tries should solve the panic then, if this is actually
>>> the cause. Generally fwohci(4) should be changed to fail if
>>> the chip doesn't become ready again after a reset instead
>>> of just ignoring that problem though. At least fwohci_reset()
>>> (there are probably more such functions in fwohci(4)) also
>>> seems to miss some bus space barriers, which also could be
>>> the cause of this panic.
>> I increased the for counter to 1000 in fwohci_reset().
>>
>>  	while(OREAD(sc, OHCI_HCCCTL) & OHCI_HCC_RESET) {
>> -		if (i++ > 100) break;
>> +		if (i++ > 1000) break;
>>  		DELAY(1000);
>>  	}
>>
>> This did not help so far.
> 
> Okay, this was my best guess based on the information
> available, sorry.

What? No sorry, thank you! The advice from you helped me to get some 
more into the deepness of FreeBSD. I was unhappy with modifying the 
source and always have to power-off to remove the card to install a new 
kernel.
I learned how to build a kernel with modules only support.
IOW, I learned how to configure and build a kernel with firewire support 
in module only. Now I can boot and install new kernels w/o plugin/off 
the card.
I see the positiv aspect here :)

And feedback form the list is very much appreciated! Writing in 
direction of /dev/null is very frustrating. Getting a feedback with an 
advice helps here a lot! Even if the advice does not give the expected 
results. But it is a feedback.

Thanks!

> 
>> I also tried to check the addresses you mentioned with l *(0xXXXX)
>> But here I miss some things. I guess I need to invoke gdb somehow?
> 
> Yes, simply `gdb /path/to/kernel.debug`

Heh, that only works when the gdb host target is from the same arch as 
the debugging target, right?
Unfortunately I build all (except ports) on a MacBook Pro VM (amd64) 
instance and install it on my Mac and Sparc. There is no second Sparc 
available.

> You might also want to bug firewire@ and simokawa@ regarding this.

I guess so since on my iMac (G3) fw support is broken also since 
r187993. But the previous revision does not help here on sparc64.
Another issue.

Thanks!
Andreas





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