Help interpreting kernel panic

Question

Hello-
I'm wondering if anyone can help me interpret a recent kernel panic. I had just woken my powerbook up from sleep and was talking one the phone. I wasn't touching the machine at all. Mail.app connected and downloaded my new email messages. Nothing else was running. Again, I didn't touch the machine. Suddenly, it panicked. The log is below, but I'm hoping someone can help shed some light on the possible causes of this panic. I've been through the entire Resolving Kernel Panics FAQ, and I've recently reinstalled. This isn't a replicate-able panic.
Thu Feb 23 20:08:47 2006
Unresolved kernel trap(cpu 0): 0x300 - Data access DAR=0x000000000800061C PC=0x00000000000A4638
Latest crash info for cpu 0:
Exception state (sv=0x221D8780)
PC=0x000A4638; MSR=0x00001030; DAR=0x0800061C; DSISR=0x40000000; LR=0x000A4584; R1=0x120E3BD0; XCP=0x0000000C (0x300 - Data access)
Backtrace:
0x01981B00 0x0002BB0C 0x002FC59C 0x002FC664 0x22295E78 0x002D28A4
0x0003C744 0x000A9894
Kernel loadable modules in backtrace (with dependencies):
com.apple.iokit.IOAudioFamily(1.5.5b2)@0x2228f000
dependency: com.apple.iokit.IOUSBFamily(2.2.8)@0x26e82000
Proceeding back via exception chain:
Exception state (sv=0x221D8780)
previously dumped as "Latest" state. skipping...
Exception state (sv=0x29FF8000)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)
Kernel version:
Darwin Kernel Version 8.4.0: Tue Jan 3 18:22:10 PST 2006; root:xnu-792.6.56.obj~1/RELEASE_PPC
panic(cpu 0 caller 0xFFFF0003): 0x300 - Data access
Latest stack backtrace for cpu 0:
Backtrace:
0x00095718 0x00095C30 0x0002683C 0x000A8384 0x000ABD00
Proceeding back via exception chain:
Exception state (sv=0x221D8780)
PC=0x000A4638; MSR=0x00001030; DAR=0x0800061C; DSISR=0x40000000; LR=0x000A4584; R1=0x120E3BD0; XCP=0x0000000C (0x300 - Data access)
Backtrace:
0x01981B00 0x0002BB0C 0x002FC59C 0x002FC664 0x22295E78 0x002D28A4
0x0003C744 0x000A9894
Kernel loadable modules in backtrace (with dependencies):
com.apple.iokit.IOAudioFamily(1.5.5b2)@0x2228f000
dependency: com.apple.iokit.IOUSBFamily(2.2.8)@0x26e82000
Exception state (sv=0x29FF8000)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)
Kernel version:
Darwin Kernel Version 8.4.0: Tue Jan 3 18:22:10 PST 2006; root:xnu-792.6.56.obj~1/RELEASE_PPC

Answer 1

Hi, Chris and Maxit —
Was this a one-time problem?
I claim no particular expertise, but I don't see much in the panic.log that helps to isolate a specific underlying cause.
That is, except for Maxit's rationale. Because the backtrace indicates that the exception occurred upon loading the IOAudioFamily .kext (driver, or extension "family"), related hardware &/or driver compatibility would typically be worth exploring. Please check to be sure that you've disconnected all non-critical peripherals & disabled login items and any "system enhancers" while you're troubleshooting this problem.
The 0x300 DAR (data access register) trap is probably the most common type of exception that causes kernel panics. It simply indicates that the processor couldn't perform a data memory access. This could be due to a programming issue or a hardware problem (e.g., "bad" RAM, HD corruption).
If the problem recurs without any more specific indication from a panic.log or, e.g., console.log entr(ies), I suggest you diligently work through the course of action presented in Resolving kernel panics.
Sorry I can't offer anything more magically insightful.
Good luck!
Dean
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