Hard crash with new snd_hda.

[Alexander Motin]

Adam McDougall wrote:
> Alexander Motin wrote:
>> Frank Mayhar wrote:
>>> Fatal trap 12: page fault while in kernel mode
>>> cpuid = 1; apic id = 01
>>> fault virtual address   = 0x14
>>> fault code              = supervisor read, page not present
>>> instruction pointer     = 0x20:0xc617e0f1
>>> stack pointer           = 0x28:0xe80697fc
>>> frame pointer           = 0x28:0xe8069828
>>> code segment            = base 0x0, limit 0xfffff, type 0x1b
>>>                         = DPL 0, pres 1, def32 1, gran 1
>>> processor eflags        = interrupt enabled, resume, IOPL = 0
>>> current process         = 1184 (kldload)
>>> trap number             = 12
>>> panic: page fault
>>> cpuid = 1
>>> Uptime: 54s
>>> Physical memory: 2003 MB
>>> Dumping 95 MB:
>>
>> This is probably the late consequence. I think debugging at this point 
>> won't give much. At least it will require deep data structures digging.
>>
>> You can enable some more debugging with setting hw.snd.verbose=4. May 
>> be it will give some clues. If not, probably we should try to add some 
>> debug printing near channel-to-device assignment loop near line 7170. 
>> We should try to find is the channel number was incorrectly set 
>> initially or it was erased later or channel memory itself was erased.
>>
>> The only idea I have now about the problem is that it may be related 
>> to the two audio codecs that you have on the same HDA bus. You are the 
>> first person who reported about such setup, so it wasn't ever tested.
>>
> I think I am having a similar issue, discovered it on a new model Dell 
> Latitude E6500.  It is probably seeing a codec for HDMI and modem in 
> addition to the normal sound. Sound works if I patch the old hda driver 
> to detect my codec on 7.1, but I just got 8 installed last night.  If I 
> have KDB_UNATTENDED and a dumpdev, it either hangs at the beginning of 
> the dump or reboots almost immediately after the panic.  I can try to 
> hook up a serial or firewire console later and gather more info, but 
> tonight I might be too busy.  In the meantime, here are two screenshots 
> of the panic and the backtrace:
> http://www.egr.msu.edu/~mcdouga9/pics/1007081830.jpg
> http://www.egr.msu.edu/~mcdouga9/pics/1007081831.jpg

I have managed to artificially reproduce your situation and I think my 
recent patch just committed to 8-CURRENT should fix the problem. Report 
me the results please.

-- 
Alexander Motin