libata-pmp-prep: implement ATA_LFLAG_NO_RETRY

Some PMP links are connected to internal pseudo devices which may come
and go depending on situation.  There's no reason to try hard to
recover them.  ATA_LFLAG_NO_RETRY tells EH to not retry if the device
attached to the link fails.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 6266fff..adeee73 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -169,6 +169,7 @@
 	ATA_LFLAG_ASSUME_ATA	= (1 << 3), /* assume ATA class */
 	ATA_LFLAG_ASSUME_SEMB	= (1 << 4), /* assume SEMB class */
 	ATA_LFLAG_ASSUME_CLASS	= ATA_LFLAG_ASSUME_ATA | ATA_LFLAG_ASSUME_SEMB,
+	ATA_LFLAG_NO_RETRY	= (1 << 5), /* don't retry this link */
 
 	/* struct ata_port flags */
 	ATA_FLAG_SLAVE_POSS	= (1 << 0), /* host supports slave dev */