hpsa: refine the pci enable/disable handling

When a second(kdump) kernel starts and the hard reset method is used
the driver calls pci_disable_device without previously enabling it,
so the kernel shows a warning -
[   16.876248] WARNING: at drivers/pci/pci.c:1431 pci_disable_device+0x84/0x90()
[   16.882686] Device hpsa
disabling already-disabled device
...
This patch fixes it, in addition to this I tried to balance also some other pairs
of enable/disable device in the driver.
Unfortunately I wasn't able to verify the functionality for the case of a sw reset,
because of a lack of proper hw.

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 8c17c432dcd5ac7e865d402c5d42d34fb2cdc9b5..7828834e212b98ab92d352b6f399c79291c99a6a 100644 (file)
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -5971,10 +5971,6 @@ static int hpsa_kdump_hard_reset_controller(struct pci_dev *pdev)
 
        /* Save the PCI command register */
        pci_read_config_word(pdev, 4, &command_register);
-       /* Turn the board off.  This is so that later pci_restore_state()
-        * won't turn the board on before the rest of config space is ready.
-        */
-       pci_disable_device(pdev);
        pci_save_state(pdev);
 
        /* find the first memory BAR, so we can find the cfg table */
@@ -6022,11 +6018,6 @@ static int hpsa_kdump_hard_reset_controller(struct pci_dev *pdev)
                goto unmap_cfgtable;
 
        pci_restore_state(pdev);
-       rc = pci_enable_device(pdev);
-       if (rc) {
-               dev_warn(&pdev->dev, "failed to enable device.\n");
-               goto unmap_cfgtable;
-       }
        pci_write_config_word(pdev, 4, command_register);
 
        /* Some devices (notably the HP Smart Array 5i Controller)
@@ -6537,6 +6528,23 @@ static int hpsa_init_reset_devices(struct pci_dev *pdev)
        if (!reset_devices)
                return 0;
 
+       /* kdump kernel is loading, we don't know in which state is
+        * the pci interface. The dev->enable_cnt is equal zero
+        * so we call enable+disable, wait a while and switch it on.
+        */
+       rc = pci_enable_device(pdev);
+       if (rc) {
+               dev_warn(&pdev->dev, "Failed to enable PCI device\n");
+               return -ENODEV;
+       }
+       pci_disable_device(pdev);
+       msleep(260);                    /* a randomly chosen number */
+       rc = pci_enable_device(pdev);
+       if (rc) {
+               dev_warn(&pdev->dev, "failed to enable device.\n");
+               return -ENODEV;
+       }
+
        /* Reset the controller with a PCI power-cycle or via doorbell */
        rc = hpsa_kdump_hard_reset_controller(pdev);
 
@@ -6545,10 +6553,11 @@ static int hpsa_init_reset_devices(struct pci_dev *pdev)
         * "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 rc; /* just try to do the kdump anyhow. */
-       if (rc)
-               return -ENODEV;
+       if (rc) {
+               if (rc != -ENOTSUPP) /* just try to do the kdump anyhow. */
+                       rc = -ENODEV;
+               goto out_disable;
+       }
 
        /* Now try to get the controller to respond to a no-op */
        dev_warn(&pdev->dev, "Waiting for controller to respond to no-op\n");
@@ -6559,7 +6568,11 @@ static int hpsa_init_reset_devices(struct pci_dev *pdev)
                        dev_warn(&pdev->dev, "no-op failed%s\n",
                                        (i < 11 ? "; re-trying" : ""));
        }
-       return 0;
+
+out_disable:
+
+       pci_disable_device(pdev);
+       return rc;
 }
 
 static int hpsa_allocate_cmd_pool(struct ctlr_info *h)
@@ -6739,6 +6752,7 @@ static void hpsa_undo_allocations_after_kdump_soft_reset(struct ctlr_info *h)
                iounmap(h->transtable);
        if (h->cfgtable)
                iounmap(h->cfgtable);
+       pci_disable_device(h->pdev);
        pci_release_regions(h->pdev);
        kfree(h);
 }