libata: implement LPM support for port multipliers

Port multipliers can do DIPM on fan-out links fine.  Implement support
for it.  Tested w/ SIMG 57xx and marvell PMPs.  Both the host and
fan-out links enter power save modes nicely.

SIMG 37xx and 47xx report link offline on SStatus causing EH to detach
the devices.  Blacklisted.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 15 insertions, 6 deletions

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index a645cd3ab163..06a4db1ec10e 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3232,7 +3232,7 @@ static int ata_eh_maybe_retry_flush(struct ata_device *dev)
 static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
                           struct ata_device **r_failed_dev)
 {
-        struct ata_port *ap = link->ap;
+        struct ata_port *ap = ata_is_host_link(link) ? link->ap : NULL;
         struct ata_eh_context *ehc = &link->eh_context;
         struct ata_device *dev, *link_dev = NULL, *lpm_dev = NULL;
         unsigned int hints = ATA_LPM_EMPTY | ATA_LPM_HIPM;
@@ -3278,9 +3278,12 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
                 }
         }
 
-        rc = ap->ops->set_lpm(link, policy, hints);
-        if (!rc && ap->slave_link)
-                rc = ap->ops->set_lpm(ap->slave_link, policy, hints);
+        if (ap) {
+                rc = ap->ops->set_lpm(link, policy, hints);
+                if (!rc && ap->slave_link)
+                        rc = ap->ops->set_lpm(ap->slave_link, policy, hints);
+        } else
+                rc = sata_pmp_set_lpm(link, policy, hints);
 
         /*
          * Attribute link config failure to the first (LPM) enabled
@@ -3412,8 +3415,14 @@ static int ata_eh_schedule_probe(struct ata_device *dev)
         ehc->saved_ncq_enabled &= ~(1 << dev->devno);
 
         /* the link maybe in a deep sleep, wake it up */
-        if (link->lpm_policy > ATA_LPM_MAX_POWER)
-                link->ap->ops->set_lpm(link, ATA_LPM_MAX_POWER, ATA_LPM_EMPTY);
+        if (link->lpm_policy > ATA_LPM_MAX_POWER) {
+                if (ata_is_host_link(link))
+                        link->ap->ops->set_lpm(link, ATA_LPM_MAX_POWER,
+                                               ATA_LPM_EMPTY);
+                else
+                        sata_pmp_set_lpm(link, ATA_LPM_MAX_POWER,
+                                         ATA_LPM_EMPTY);
+        }
 
         /* Record and count probe trials on the ering.  The specific
          * error mask used is irrelevant.  Because a successful device