On Mon, Jan 16, 2012 at 9:11 PM, Dan Williams [off-list ref] wrote:

This is called per-sdev but in the sas-transport case this waits for the
entire domain to recover which is never guaranteed to be less than 120
seconds with libata taking nearly a minute per-device to recover.  Ping
the waitqueue so that the hung task timer knows we're still making
progress.

I'm now not so sure about this one.  This was implemented before the
change to asynchronously scan ata devices where serial discover could
take inordinate amounts of time.

Jack already reported a scan time reduction of 3 minutes down to 5
seconds with the async code, so I'll drop this patch.

Even if recovery was taking a long time this patch would only move the
hung task timeout backtrace to another location in the kernel that was
dependent on the completion of error handling.

--
Dan