Re: libata machine check on Alpha

[Jeff Garzik <jeff@garzik.org>]

Albert Lee wrote:
> Tejun Heo wrote:
>> Albert Lee wrote:
>>
>>> Tejun Heo wrote:
>>>
>>>> Jonathan Blake Benson wrote:
>>>>
>>>>> I posted a couple of months ago regarding enabling libata.atapi on a
>>>>> Digital Alpha 164LX, equipped with a Silicon Image 3114 controller.  I
>>>>> decied to give kernel 2.6.16 (release, was previously using rc-1) a
>>>>> shot, and it no longer longer panics.  I still have a Lite-ON DVD ROM
>>>>> drive connected via a sil3611 bridge to port number 4, hoping that I
>>>>> can avoid using the onboard CMD646.
>>>>>
>>>>> No panic this time, though it appears to throw a machine check.  The
>>>>> system continues all the way to multi-user, and the Maxtor drives are
>>>>> usable.  Hope the attached dmesg helps.  Let me know if I can be of
>>>>> any assitance.
>>>>>
>>>> Can you build your kernel with ATA_DEBUG set and post dmesg?  Just
>>>> change #undef ATA_DEBUG to #define ATA_DEBUG at the top of
>>>> include/linux/libata.h
>>>>
>>> For the SiI 3611 bridge + ATAPI devices, maybe the ATAPI_ENABLE_DMADIR
>>> workaround should also be turned on as well. (in linux/libata.h)
>>>
>>> My JMicron 20330 bridge + SiI 3112 can handle ATAPI DMA without
>>> the ATAPI_ENABLE_DMADIR workaround. However, the SiI 3611 bridge seems
>>> need it.
>>
>> Is there any way to make this thing automatic?  'Recompile with #define
>> tweak if you have some invisible bridge chip' doesn't sound too hot.
>>
> 
> The bridge is transparent to the software. So, it's hard to detect the chip
> used. Maybe the SiImage developers know how to detect the chip?

There's a spec for DMADIR on t13.org, with IDENTIFY DEVICE bits to 
recognize, etc.

	Jeff