1 files changed, 51 insertions, 9 deletions

diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 9173d8f2ce5d..0e66f140e53b 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -1318,20 +1318,58 @@ static void ata_eh_report(struct ata_port *ap)
         }
 }
 
-static int ata_eh_reset(struct ata_port *ap, ata_reset_fn_t softreset,
+static int ata_eh_reset(struct ata_port *ap,
+                        ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
                         ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 {
         struct ata_eh_context *ehc = &ap->eh_context;
         unsigned int classes[ATA_MAX_DEVICES];
         int tries = ATA_EH_RESET_TRIES;
+        unsigned int action;
         ata_reset_fn_t reset;
         int i, rc;
 
+        /* Determine which reset to use and record in ehc->i.action.
+         * prereset() may examine and modify it.
+         */
+        action = ehc->i.action;
+        ehc->i.action &= ~ATA_EH_RESET_MASK;
         if (softreset && (!hardreset || (!sata_set_spd_needed(ap) &&
-                                         !(ehc->i.action & ATA_EH_HARDRESET))))
-                reset = softreset;
+                                         !(action & ATA_EH_HARDRESET))))
+                ehc->i.action |= ATA_EH_SOFTRESET;
         else
+                ehc->i.action |= ATA_EH_HARDRESET;
+
+        if (prereset) {
+                rc = prereset(ap);
+                if (rc) {
+                        ata_port_printk(ap, KERN_ERR,
+                                        "prereset failed (errno=%d)\n", rc);
+                        return rc;
+                }
+        }
+
+        /* prereset() might have modified ehc->i.action */
+        if (ehc->i.action & ATA_EH_HARDRESET)
                 reset = hardreset;
+        else if (ehc->i.action & ATA_EH_SOFTRESET)
+                reset = softreset;
+        else {
+                /* prereset told us not to reset, bang classes and return */
+                for (i = 0; i < ATA_MAX_DEVICES; i++)
+                        classes[i] = ATA_DEV_NONE;
+                return 0;
+        }
+
+        /* did prereset() screw up?  if so, fix up to avoid oopsing */
+        if (!reset) {
+                ata_port_printk(ap, KERN_ERR, "BUG: prereset() requested "
+                                "invalid reset type\n");
+                if (softreset)
+                        reset = softreset;
+                else
+                        reset = hardreset;
+        }
 
  retry:
         ata_port_printk(ap, KERN_INFO, "%s resetting port\n",
@@ -1424,6 +1462,7 @@ static int ata_port_nr_enabled(struct ata_port *ap)
 /**
  *      ata_eh_recover - recover host port after error
  *      @ap: host port to recover
+ *      @prereset: prereset method (can be NULL)
  *      @softreset: softreset method (can be NULL)
  *      @hardreset: hardreset method (can be NULL)
  *      @postreset: postreset method (can be NULL)
@@ -1440,8 +1479,8 @@ static int ata_port_nr_enabled(struct ata_port *ap)
  *      RETURNS:
  *      0 on success, -errno on failure.
  */
-static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset,
-                          ata_reset_fn_t hardreset,
+static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
+                          ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
                           ata_postreset_fn_t postreset)
 {
         struct ata_eh_context *ehc = &ap->eh_context;
@@ -1469,7 +1508,8 @@ static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset,
         if (ehc->i.action & ATA_EH_RESET_MASK) {
                 ata_eh_freeze_port(ap);
 
-                rc = ata_eh_reset(ap, softreset, hardreset, postreset);
+                rc = ata_eh_reset(ap, prereset, softreset, hardreset,
+                                  postreset);
                 if (rc) {
                         ata_port_printk(ap, KERN_ERR,
                                         "reset failed, giving up\n");
@@ -1586,6 +1626,7 @@ static void ata_eh_finish(struct ata_port *ap)
 /**
  *      ata_do_eh - do standard error handling
  *      @ap: host port to handle error for
+ *      @prereset: prereset method (can be NULL)
  *      @softreset: softreset method (can be NULL)
  *      @hardreset: hardreset method (can be NULL)
  *      @postreset: postreset method (can be NULL)
@@ -1595,11 +1636,12 @@ static void ata_eh_finish(struct ata_port *ap)
  *      LOCKING:
  *      Kernel thread context (may sleep).
  */
-void ata_do_eh(struct ata_port *ap, ata_reset_fn_t softreset,
-               ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
+void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
+               ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
+               ata_postreset_fn_t postreset)
 {
         ata_eh_autopsy(ap);
         ata_eh_report(ap);
-        ata_eh_recover(ap, softreset, hardreset, postreset);
+        ata_eh_recover(ap, prereset, softreset, hardreset, postreset);
         ata_eh_finish(ap);
 }