Re: [patch 2/2] sata_via: Delay on vt6420 when starting ATAPI DMA write

From: Bart Hartgers
Date: Wed Jan 20 2010 - 01:44:27 EST


2010/1/20 Tejun Heo <htejun@xxxxxxxxx>:
> Hello,
> On 01/17/2010 08:56 AM, Bart Hartgers wrote:
>> When writing a disc on certain lite-on dvd-writers (also rebadged as
>> optiarc/LG/...) connected to a vt6420, the ATAPI CDB ends up in the
>> datastream and on the disc, causing silent corruption. ÂDelaying
>> between sending the CDB and starting DMA seems to prevent this.
>> I do not know if there are burners that do not suffer from this, but
>> the patch should be safe for those as well.
>> There are many reports of this issue, but AFAICT no solution was
>> found before. For example:
>> Signed-off-by: Bart Hartgers <bart.hartgers@xxxxxxxxx>
> Ah... you found solution for this? ÂThat's great. ÂThis is one of the
> three problems that have been lingering for years - the other two
> being pata_ali ATAPI DMA problem and sata_sil data corruption problem.
> I'll be ecstatic if this fix works. ÂJust one thing, I don't think
> we'll need a warning message there. ÂIt's useful during development
> but it doesn't really provide any useful information afterwards.

Yes, you're right. I'll drop the printk_once and send another patch
for inclusion. However, for testing I found it very useful to make
sure that I got the right module loaded. So I figured it could be
helpful for the interpretation of success/failure reports.

Assuming that this patch works for other people as well, what is
prefered: resending both patches or just to make a new #2/2 (the
vt6420 one)?


> Digging up the mailing list and cc'ing people who have reported this
> problem. ÂIf you still have the affected systems, can you guys please
> test the patch in the following message and see whether it fixes the
> problem?
> Â
> Thanks a lot. Â:-)
> --
> tejun

Bart Hartgers - New e-mail: bart.hartgers@xxxxxxxxx
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