Interestingly, when SIDPR is used in ata_piix, writes to DET in
SControl sometimes get ignored leading to detection failure.  Update
sata_link_resume() such that it reads back SControl after clearing DET
and retry if it's not clear.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: Nfengxiangjun <fengxiangjun@neusoft.com>
Reported-by: NJim Faulkner <jfaulkne@ccs.neu.edu>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>