tree 3c2b16121143c4dad805b048b2cee5d4c410384a
parent 6ddd68615ae9b21096545d7d6ab0f04113ae8b42
author Jeff Garzik <jeff@garzik.org> 1204231428 -0500
committer Jeff Garzik <jeff@garzik.org> 1204721586 -0500

ahci: work around ATI SB600 h/w quirk

This addresses the recent ATI SB600 errata, where the hardware does
not like 256-length PRD entries during FPDMA (aka NCQ).

It hurts performance on SB600, but it is more important to get a
correct patch eliminating the data corruption/lockups, and then later
on tune for performance.

We simply limit each command to a maximum of 255 sectors, on SB600.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>