[alsa-devel] crash/reboot with rawmidi on ice1712 dual opteron

[Takashi Iwai]

At Tue, 24 Apr 2007 15:23:52 +0100,
Daniel James wrote:
> 
> Hi Takashi, hi Florian,
> 
> I found a similar MIDI crashing bug on a dual Opteron machine in 2005, 
> even with only one processor installed, which I reported at the time on 
> alsa-devel. The card was an M-Audio Audiophile 24/96, normally reliable.
> 
> I couldn't replicate this problem on an Asus single processor Opteron 
> board, so I concluded it was a quirk of my dual socket Tyan S2875 
> motherboard:
> 
> http://article.gmane.org/gmane.linux.alsa.devel/24682/
> http://article.gmane.org/gmane.linux.alsa.devel/25323/
> 
> Last time I tested it, earlier this year I think, the bug was still 
> there. I even flashed the BIOS of the Tyan board in case it was a BIOS 
> bug, but it made no difference. I installed a 32-bit distro and that 
> made no difference either.
> 
> Maybe there is something more generally wrong here, which only affects 
> dual-processor AMD64 hardware. I can make the Tyan machine available 
> over SSH if that helps, it has a fixed IP address.

The most important thing is to find out what triggers which result.
As far as I understand from Florian's analysis, the io-port access
results in a machine reboot, not a kernel panic or so.  It's scary
because the controls is completely out of kernel.

Perhaps an easiest but foolishest way to trace this is to put printk
at each io-port access and any other important points, and give some
sleep at each point, then watch the kernel message.  You can get rid
of spin_lock_*() around that, just for testing.


Takashi