Fatal TIMEOUT - WRITE_DMA errors return with ATA Mk.III

[Søren Schmidt]

Paul Mather wrote:
> Since somewhere in the 5.x release cycle, my system has fallen prey to
> the "TIMEOUT - WRITE_DMA" errors which result in the drive becoming
> detached (which causes my geom_mirror to break and require rebuilding).
> According to smartctl and disk diagnostics, there's nothing wrong with
> my drives.  Plus, the problem does not manifest itself under 4-STABLE.
> (I'm not the only one to have reported this problem.)
> 
> Lately, I'd had success using a patch posted to freebsd-current by Ian
> Dowse.  The "TIMEOUT - WRITE_DMA" errors still occurred, but they
> weren't fatal.  I updated my kernel and world recently, and, alas, the
> "TIMEOUT - WRITE_DMA" problem has returned once more:

You should try a recent -current, I committed cleanups to the timeout 
system on the 21'st. You might still have timeouts (which might due to 
non-ATA issues) but they should not be fatal unless the HW really does 
screw up..

-- 

-Søren