libata: force hardreset if link is in powersave mode

Inhibiting link PM mode doesn't bring the link back online if it's
already in powersave mode.  If SRST is used in these cases, libata EH
thinks that the link is offline and fails detection.  Force hardreset
if link is in powersave mode.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index be95fdb6972680dd9ea12193599ae25827f28b2c..92da864a8bf1120ac19ec3eb7ad87e0349fae7c2 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3947,6 +3947,7 @@ int ata_std_prereset(struct ata_link *link, unsigned long deadline)
        struct ata_port *ap = link->ap;
        struct ata_eh_context *ehc = &link->eh_context;
        const unsigned long *timing = sata_ehc_deb_timing(ehc);
+       u32 sstatus;
        int rc;
 
        /* handle link resume */
@@ -3960,6 +3961,17 @@ int ata_std_prereset(struct ata_link *link, unsigned long deadline)
        if (ap->flags & ATA_FLAG_PMP)
                ehc->i.action |= ATA_EH_HARDRESET;
 
+       /* if link powersave is on, force hardreset */
+       if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0) {
+               u8 ipm = sstatus >> 8;
+
+               if (ipm == 2 || ipm == 6) {
+                       ata_link_printk(link, KERN_INFO, "link in powersave "
+                               "mode (ipm=%d), forcing hardreset\n", ipm);
+                       ehc->i.action |= ATA_EH_HARDRESET;
+               }
+       }
+
        /* if we're about to do hardreset, nothing more to do */
        if (ehc->i.action & ATA_EH_HARDRESET)
                return 0;