On Fri, Jan 7, 2011 at 4:01 PM, Tejun Heo [off-list ref] wrote:

On Thu, Jan 06, 2011 at 07:26:35PM +0100, Peter Zijlstra wrote:

quoted

Jeff, Tejun, could you look at the ata-eh thing, then I'll put sorting
through the futex thing on my todo list.

Hmm... I think the ->eng_timeout path is already dead.  We no longer
have any in-kernel implementation, so killing spin_unlock_wait()
should be fine.  I'll follow up with removal of the unused callback.

Unfortunately...  libsas continues to avoid the new EH :(

It's a hairy mess to untangle, too.  libata does proper error handling
of ATA device errors, notably NCQ error handling, which libsas sorely
misses.  But libata new EH assumes a bit too much about "owning" the
entirety of the EH process.  These assumptions are proper for wholly
ATA drivers (drivers/ata/*) where new EH can drive the EH process, but
in the SAS situation, a phy in SATA mode is simply a subset of a
larger set of EH conditions that must be handled.

Thus libsas uses the ancient libata hook ->phy_reset and lacks ->error_handler.

I think libata's old-EH path is entirely SAS-specific at this point.

     Jeff


P.S.  Note that libsas and ipr are peers; thus ipr driver also uses old EH.
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