[SCSI] hpsa: add 5 second delay after doorbell reset

The hardware guys tell us that after initiating a software
reset via the doorbell register we need to wait 5 seconds before
attempting to talk to the board *at all*.  This means that we
cannot watch the board to verify it transitions from "ready" to
to "not ready" then back "ready", since this transition will
most likely happen during those 5 seconds (though we can still
verify the reset happens by watching the "driver version" field
get cleared.)

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index c3db9bb..2a71ab9 100644 (file)
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -3785,6 +3785,13 @@ static int hpsa_controller_hard_reset(struct pci_dev *pdev,
                 */
                dev_info(&pdev->dev, "using doorbell to reset controller\n");
                writel(use_doorbell, vaddr + SA5_DOORBELL);
+
+               /* PMC hardware guys tell us we need a 5 second delay after
+                * doorbell reset and before any attempt to talk to the board
+                * at all to ensure that this actually works and doesn't fall
+                * over in some weird corner cases.
+                */
+               msleep(5000);
        } else { /* Try to do it the PCI power state way */
 
                /* Quoting from the Open CISS Specification: "The Power
@@ -3981,15 +3988,22 @@ static int hpsa_kdump_hard_reset_controller(struct pci_dev *pdev)
           need a little pause here */
        msleep(HPSA_POST_RESET_PAUSE_MSECS);
 
-       /* Wait for board to become not ready, then ready. */
-       dev_info(&pdev->dev, "Waiting for board to reset.\n");
-       rc = hpsa_wait_for_board_state(pdev, vaddr, BOARD_NOT_READY);
-       if (rc) {
-               dev_warn(&pdev->dev,
-                       "failed waiting for board to reset."
-                       " Will try soft reset.\n");
-               rc = -ENOTSUPP; /* Not expected, but try soft reset later */
-               goto unmap_cfgtable;
+       if (!use_doorbell) {
+               /* Wait for board to become not ready, then ready.
+                * (if we used the doorbell, then we already waited 5 secs
+                * so the "not ready" state is already gone by so we
+                * won't catch it.)
+                */
+               dev_info(&pdev->dev, "Waiting for board to reset.\n");
+               rc = hpsa_wait_for_board_state(pdev, vaddr, BOARD_NOT_READY);
+               if (rc) {
+                       dev_warn(&pdev->dev,
+                               "failed waiting for board to reset."
+                               " Will try soft reset.\n");
+                       /* Not expected, but try soft reset later */
+                       rc = -ENOTSUPP;
+                       goto unmap_cfgtable;
+               }
        }
        rc = hpsa_wait_for_board_state(pdev, vaddr, BOARD_READY);
        if (rc) {