Re: [PATCH #upstream-fixes 2/2] libata: implement ATAPI_HORKAGE_NOPIO and apply it to GGW-H10N

[Tejun Heo <tj@kernel.org>]

Alan Cox wrote:
> On Tue, 17 Jun 2008 12:37:24 +0900
> Tejun Heo <tj@kernel.org> wrote:
> 
>> LG blueray drive GGW-H10N can't do ATAPI PIO.  Implement
>> ATAPI_HORKAGE_NOPIO and apply it to the drive.  If the horkage is
>> active, atapi_check_dma() always returns 0 and warns if the controller
>> needs ATAPI PIO for certain commands.
> 
> This all seems wildly improbable as a drive with such a bug would not
> appear to be going to work in Windows. I'd like to know more and see more
> than one bug report for that drive before it goes in
> 
> You might even be looking at a single drive with a one off wiring flaw or
> chip fault at this point.

I thought it was improbable too but it's a brand new relatively cheap
blueray writer so it's quite possible that they screwed up the firmware
on this one as are often the cases for first gen devices.

Relatively cheap it may be, it's still around $300, so I don't think
I'll get one for testing.  The high price could probably explain low
error report rate.

Luke, what happens if you use the drive on windows?  Does it just work?

> So in the absence of multiple reports of this drive failing, and
> of no other drive being tested on the same controller after the bug was
> seen I think this is a *very bad idea* as a patch.

Well, if the diagnose is correct, the patch itself is just implementing
what should be done.  I agree the problem itself is very nasty but don't
think the patch is too bad given the problem.

Thanks.

-- 
tejun