cciss: forbid hard reset of 640x boards

[karo-tx-linux.git] / drivers / block / cciss.c

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 6d4c4f227d55bd1314c2aefaa83abc06dabb86cd..2abe6df9445e2845f8c0eabd228385c209a138b2 100644 (file)
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -4495,6 +4495,7 @@ static __devinit int cciss_kdump_hard_reset_controller(struct pci_dev *pdev)
        int rc, i;
        CfgTable_struct __iomem *cfgtable;
        bool use_doorbell;
+       u32 board_id;
 
        /* For controllers as old a the p600, this is very nearly
         * the same thing as
@@ -4517,6 +4518,19 @@ static __devinit int cciss_kdump_hard_reset_controller(struct pci_dev *pdev)
         * using the doorbell register.
         */
 
+       /* Exclude 640x boards.  These are two pci devices in one slot
+        * which share a battery backed cache module.  One controls the
+        * cache, the other accesses the cache through the one that controls
+        * it.  If we reset the one controlling the cache, the other will
+        * likely not be happy.  Just forbid resetting this conjoined mess.
+        */
+       cciss_lookup_board_id(pdev, &board_id);
+       if (board_id == 0x409C0E11 || board_id == 0x409D0E11) {
+               dev_warn(&pdev->dev, "Cannot reset Smart Array 640x "
+                               "due to shared cache module.");
+               return -ENODEV;
+       }
+
        for (i = 0; i < 32; i++)
                pci_read_config_word(pdev, 2*i, &saved_config_space[i]);
 
@@ -4600,7 +4614,8 @@ static __devinit int cciss_init_reset_devices(struct pci_dev *pdev)
 
        /* -ENOTSUPP here means we cannot reset the controller
         * but it's already (and still) up and running in
-        * "performant mode".
+        * "performant mode".  Or, it might be 640x, which can't reset
+        * due to concerns about shared bbwc between 6402/6404 pair.
         */
        if (rc == -ENOTSUPP)
                return 0; /* just try to do the kdump anyhow. */