Re: sata_svw data corruption, strange problems

From: Tejun Heo
Date: Mon Jun 23 2008 - 04:23:59 EST


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@xxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

--
tejun
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