Re: [PATCH Linux 2.6.12 00/09] NCQ: generic NCQ completion/error-handling

[Jens Axboe <axboe@suse.de>]

On Fri, Jul 01 2005, Tejun wrote:
> On Thu, Jun 30, 2005 at 05:26:20PM +0200, Jens Axboe wrote:
> > On Thu, Jun 30 2005, Tejun Heo wrote:
> > > Jens Axboe wrote:
> > > >On Mon, Jun 27 2005, Jens Axboe wrote:
> > > >
> > > >>On Mon, Jun 27 2005, Tejun Heo wrote:
> > > >>
> > > >>>Hello, Jeff.
> > > >>>Hello, Jens.
> > > >>>
> > > >>>This patchset implements generic completion and error-handling for
> > > >>>NCQ commands.  This patchset assumes that the previous six misc
> > > >>>patches to NCQ are applied.
> > > >>
> > > >>Excellent, much needed work in that area. I will give it a test spin
> > > >>here as well, I have one drive that likes to barf with ncq occasionally.
> > > >
> > > >
> > > >Ok, I've run with this for a few days and finally hit the
> > > >drive-stops-responding condition yesterday afternoon. Error recovery
> > > >worked a lot better than before, but eventually went down anyways. But
> > > >now I got a better look at the error, and it's the drive throwing an
> > > >ICRC (error 0x80). Very odd. I've never seen this happen with non-NCQ
> > > >operations, however I've seen it now a few times using NCQ. Any ideas?
> > > >
> > > 
> > >  Hello, Jens.
> > > 
> > >  Can you please describe how the drive went down in detail?  If 
> > > possible, log messages w/ the debug message patch applied would be 
> > > great.  As the EH now resets both the controller (on entry to EH) and 
> > > the drive (on timeout), we should be able to recover unless something 
> > > goes very strange.
> > 
> > I'm pretty sure it wasn't the fault of the error handling, although I
> > cannot say for sure of course. I don't have the log safed, but what
> > happened was that the drive threw an 0x80 icrc error, drive was
> > COMRESET, io was errored, and then nothing happened after that. Access
> > to the drive hung.
> > 
> > I will save the log the next time it occurs, I could not this time since
> > I was working on the machine remotely and needed it rebooted.
> > 
> > >  I'm currently trying to rewrite sil24 driver to make it look saner and 
> > > support NCQ.  Once I'm done with it (maybe one or two more days... I 
> > > hope), I'll do the second take of generic NCQ patches including ATAPI EH 
> > > fix and stuff and it would be great to have your failure log message 
> > > before doing that.
> > 
> > It should trigger again within a day or two, I will send it when it
> > does. Can you resend the debug patch?
> > 
> > -- 
> > Jens Axboe
> 
> 
>  Hi, Jens.
> 
>  I converted most of debug messages I've used during development into
> warning messages when posting the patchset and forgot about it, so
> I've never posted the debug patch.  Sorry about that.  Here's a small
> patch which adds some more messages though.  The following patch also
> adds printk'ing FIS on each command issue in ahci.c:ahci_qc_issue(),
> if you think it would fill your log excessively, feel free to turn it
> off.  It wouldn't probably matter anyway.

I will have to kill the issue part of the patch, that would generate
insane amounts of printk traffic :-)

I'll boot the kernel and report what happens.

-- 
Jens Axboe