tree aac59bb9fdb5e39b2f31c97be3bf92591a005059
parent dae77214fa71898b84514e43721fb7bf260b026a
author Shaohua Li <shaohua.li@intel.com> 1258336565 +0800
committer Jeff Garzik <jgarzik@redhat.com> 1259826394 -0500

ahci: disable SNotification capability for ich8

I obseved there is a sata_async_notification() for every ahci
interrupt. But the async notification does nothing (this is hard
disk drive and no pmp). This cause cpu wastes some time on sntf
register access.

It appears ICH AHCI doesn't support SNotification register, but the
controller reports it does. After quirking it, the async notification
disappears.

PS. it appears all ICH don't support SNotification register from ICH
manual, don't know if we need quirk all ICH. I don't have machines
with all kinds of ICH.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>