libata-pmp-prep: implement ATA_LFLAG_DISABLED

Implement ATA_LFLAG_DISABLED.  The flag indicates the link is disabled
due to EH recovery failure.  While a link is disabled, no EH action is
taken on the link and suspend/resume become noop too.

This will be used by PMP links to manage failed links.

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 adeee73..2bd1d26 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -170,6 +170,7 @@
 	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 */
+	ATA_LFLAG_DISABLED	= (1 << 6), /* link is disabled */
 
 	/* struct ata_port flags */
 	ATA_FLAG_SLAVE_POSS	= (1 << 0), /* host supports slave dev */
@@ -289,6 +290,7 @@
 	ATA_EH_REVALIDATE	= (1 << 0),
 	ATA_EH_SOFTRESET	= (1 << 1),
 	ATA_EH_HARDRESET	= (1 << 2),
+	ATA_EH_ENABLE_LINK	= (1 << 3),
 
 	ATA_EH_RESET_MASK	= ATA_EH_SOFTRESET | ATA_EH_HARDRESET,
 	ATA_EH_PERDEV_MASK	= ATA_EH_REVALIDATE,
@@ -999,6 +1001,7 @@
 {
 	ata_ehi_schedule_probe(ehi);
 	ehi->flags |= ATA_EHI_HOTPLUGGED;
+	ehi->action |= ATA_EH_ENABLE_LINK;
 	ehi->err_mask |= AC_ERR_ATA_BUS;
 }