1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 7e2a1b38093e..6686dbec4440 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1267,9 +1267,11 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class,
 {
         struct ata_port *ap = link->ap;
         struct ahci_host_priv *hpriv = ap->host->private_data;
+        struct ahci_port_priv *pp = ap->private_data;
         const char *reason = NULL;
         unsigned long now, msecs;
         struct ata_taskfile tf;
+        bool fbs_disabled = false;
         int rc;
 
         DPRINTK("ENTER\n");
@@ -1279,6 +1281,16 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class,
         if (rc && rc != -EOPNOTSUPP)
                 ata_link_warn(link, "failed to reset engine (errno=%d)\n", rc);
 
+        /*
+         * According to AHCI-1.2 9.3.9: if FBS is enable, software shall
+         * clear PxFBS.EN to '0' prior to issuing software reset to devices
+         * that is attached to port multiplier.
+         */
+        if (!ata_is_host_link(link) && pp->fbs_enabled) {
+                ahci_disable_fbs(ap);
+                fbs_disabled = true;
+        }
+
         ata_tf_init(link->device, &tf);
 
         /* issue the first D2H Register FIS */
@@ -1319,6 +1331,10 @@ int ahci_do_softreset(struct ata_link *link, unsigned int *class,
         } else
                 *class = ahci_dev_classify(ap);
 
+        /* re-enable FBS if disabled before */
+        if (fbs_disabled)
+                ahci_enable_fbs(ap);
+
         DPRINTK("EXIT, class=%u\n", *class);
         return 0;