Tejun Heo a écrit :
> Rafael J. Wysocki wrote:
>   
>> [Adding CCs.]
>>
>> On Tuesday, 1 of July 2008, Mathieu Bérard wrote:
>>     
>>> Hi,
>>> I have a laptop with an ICH6M SATA Controller and a Hitachi hard drive.
>>> While it worked well using the ahci module and Linux 2.6.25, 
>>> it get randomly 'stuck' for several seconds to several minutes with 2.6.26-rc8.
>>> Successive errors progressively reduce the ATA link speed.
>>>
>>> Passing the libata.noacpi parameter is an effective workaround.
>>>
>>> Please note that it's not the first time i have this kind of issue, see:
>>> http://marc.info/?l=linux-ide&m=117305595312399&w=2
>>> This was found to be a bad interaction between my _GTF taskfile, which enable the
>>> "Enable Device-Initiated Interface Power State Transitions" feature, and NCQ.
>>> The driver was later NCQ blacklisted to correct the problem.
>>>       
>
> Can you please post the result of "hdparm -I /dev/sda" and full kernel
> boot log?  0xca is not a NCQ command so the it's not related to NCQ at
> all.  It seems we'll need to filter out DIPM commands from _GTF.
>
>   
Hi,
hdparm and dmesg output attached.

I was not expecting anything related to NCQ as my drive is blacklisted,
I was just mentioning previous issue with that hardware.

Do you know what has changed in this version that is now causing failure
with DIPM ?  I could bisect to try to find out, but this will be painful
as the
device hang may only appears after several minutes of disk activity.


-- 
Mathieu