Re: [Regression] 2.6.28-rc1 (2fca5c): libata: kernel cant boot (was: Re: 2.6.27-rc1 (2fca5c): libata: kernel cant boot)

[Jens Axboe <jens.axboe@oracle.com>]

On Fri, Oct 24 2008, Rafael J. Wysocki wrote:
> On Friday, 24 of October 2008, Jens Axboe wrote:
> > On Fri, Oct 24 2008, Rafael J. Wysocki wrote:
> > > On Friday, 24 of October 2008, Jens Axboe wrote:
> > > > On Fri, Oct 24 2008, Alexander Beregalov wrote:
> > > > > Hi
> > > > > 
> > > > > commit 2fca5ccf97d2c28bcfce44f5b07d85e74e3cd18e
> > > > > Author: Jens Axboe <jens.axboe@oracle.com>
> > > > > Date:   Wed Oct 22 09:34:49 2008 +0200
> > > > > 
> > > > >     libata: switch to using block layer tagging support
> > > > > 
> > > > > 
> > > > > This kernel can not read even 0 sector on disk with rootfs. It
> > > > > initialized disk, but cant read it at all.
> > > > >  CMD646 on Sparc
> > > > > 
> > > > > Rverting helped.
> > > 
> > > Confirmed on hp nx6325 w/ pata_atiixp (apparently, SCSI commands time out).
> > 
> > Basically it'll dererence ->qcmd[] with -1 index so it'll break in
> > various interesting ways, I'm sure.
> > 
> > > Reverting the commit also helps here.
> > > 
> > > [I guess it's going to break things left and right.]
> > 
> > Indeed.
> > 
> > > > Doh, how annoying! What driver does that controller use? PATA doesn't
> > > > even use NCQ, so it's a bit of an oddity that it makes a difference at
> > > > all.
> > > > 
> > > > Can you provide the boot messages?
> > > 
> > > If I'm able to reproduce the breakage of Asus L5D, I will.
> > 
> > I don't need that anymore, I realized the mistake right after sending
> > that.
> 
> The fix you posted helps here too. :-)

Good, please boot your regression time machine and get it committed
before -rc1 was released :-)

-- 
Jens Axboe