Hello, Alexander.

On Mon, Aug 01, 2016 at 12:27:18AM +0500, Alexander Kandaurov wrote:

A possible fix to this issue could be using PIO for the misc ATAPI
commands for this controller as is done in sata_promise.c, but what
confuses me here is that two other systems perform well in similar
conditions, so this could possibly be specifically some Linux bug.

Thanks a lot for the detailed investigation.  It could well be some
peculiarities from the way linux driver behave but given how long the
controller has been out of production, I'd be completely happy with a
crude PIO hammer fix.  It's not like these misc commands benefit a lot
from DMA anyway.

Thanks.

-- 
tejun