Re: [PATCH 00/12] Roll-up of sas_ata patches

["Darrick J. Wong" <djwong@us.ibm.com>]

James Bottomley wrote:

> There's a problem somewhere with your error handler changes (which I
> picked up thanks to the problems with the V28 firmware).  What I see
> without your changes is that for a directly attached SATA device, when
> the firmware begins its death spiral, the commands all return and
> eventually send I/O errors to the filesystem,  With your patch series
> applied, it just loops forever giving messages like:
> 
> Feb  3 12:07:06 localhost kernel: aic94xx: escb_tasklet_complete: phy5: LINK_RESET_ERROR
> Feb  3 12:07:06 localhost kernel: aic94xx: phy5: Receive FIS timeout
> Feb  3 12:07:06 localhost kernel: aic94xx: phy5: retries:0 performing link reset seq
> Feb  3 12:07:06 localhost kernel: sas: --- Exit sas_scsi_recover_host
> Feb  3 12:07:06 localhost kernel: aic94xx: control_phy_tasklet_complete: phy5, lrate:0x8, proto:0xe
> Feb  3 12:07:06 localhost kernel: sas: Enter sas_scsi_recover_host
> Feb  3 12:07:06 localhost kernel: sas: --- Exit sas_scsi_recover_host
> Feb  3 12:07:06 localhost kernel: sas: Enter sas_scsi_recover_host
> Feb  3 12:07:06 localhost kernel: sas: --- Exit sas_scsi_recover_host
> Feb  3 12:07:06 localhost kernel: sas: Enter sas_scsi_recover_host
> Feb  3 12:07:06 localhost kernel: sas: --- Exit sas_scsi_recover_host

Interesting, since the opposite happens with SAS disks. :)

The infinite loop is usually what happens if a scsi_cmnd gets pulled off
the eh queue without being scsi_eh_finish_cmnd()'d.  Can you send me the
whole dmesg?  It's possible that we're trying to abort a command, which
of course fails for a SATA disk, so we try bigger and bigger hammers....
and the big hammers don't call scsi-eh-finish-cmd.

Did these SATA link reset errors only start showing up after the v28
firmware patch, or has this always happened?  I've noticed lately that I
get link reset errors if I run a short exercise on an ext3 filesystem on
a SATA disk, yet dd exercise runs just fine.  But I had also thought
that it was just my flaky hardware. :)

--D