cciss: do not use bit 2 doorbell reset

It causes NMIs which are undesirable at best, unsurvivable at worst.
Prefer the soft reset instead.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 865484e40841..9528e94dc8b2 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -4673,8 +4673,14 @@ static __devinit int cciss_kdump_hard_reset_controller(struct pci_dev *pdev)
                 use_doorbell = DOORBELL_CTLR_RESET2;
         } else {
                 use_doorbell = misc_fw_support & MISC_FW_DOORBELL_RESET;
-                if (use_doorbell)
-                        use_doorbell = DOORBELL_CTLR_RESET;
+                if (use_doorbell) {
+                        dev_warn(&pdev->dev, "Controller claims that "
+                                "'Bit 2 doorbell reset' is "
+                                "supported, but not 'bit 5 doorbell reset'.  "
+                                "Firmware update is recommended.\n");
+                        rc = -ENOTSUPP; /* use the soft reset */
+                        goto unmap_cfgtable;
+                }
         }
 
         rc = cciss_controller_hard_reset(pdev, vaddr, use_doorbell);