Re: sata_svw data corruption, strange problems

[Tejun Heo <tj@kernel.org>]

Pavel Machek wrote:
> Hi!
> 
>>> I see strange problems on machine with sata_svw. The machine seems to
>>> corrupt data every few days (ext3 error, dir index corrupted), and has
>>> some other very strange problems (keyboard misbehaves, pulling out
>>> SATA disk cures it, see
>>> https://bugzilla.novell.com/show_bug.cgi?id=400772 ).
>>>
>>> Then I got to the comment 
>>>
>>>         writeb(dmactl | ATA_DMA_START, mmio + ATA_DMA_CMD);
>>>         /* There is a race condition in certain SATA controllers
>>> that can be seen when the r/w command is given to the controller
>>> before the host DMA is started. On a Read command, the controller
> ...
>>> ...and that would certainly explain what we are seeing. Are
>>> serverworks controllers broken by design?
>> The comment looks like a warning to me as the DMA engine is started
>> before the command is issued to the drive as explained in the next
>> comment.
> 
> Ok, what about this?
> 
> ---
> 
> Clarify data corruption comment.
> 
> Signed-off-by: Pavel Machek <pavel@suse.cz>

Acked-by: Tejun Heo <tj@kernel.org>

-- 
tejun