[PATCH 3.10 11/22] hpsa: refine the pci enable/disable handling

Greg Kroah-Hartman
2015-07-01T18:41:47Z

From: Tomas Henzl <thenzl@redhat.com>

commit 132aa220b45d60e9b20def1e9d8be9422eed9616 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/hpsa.c | 42 ++++++++++++++++++++++++++++--------------
1 file changed, 28 insertions(+), 14 deletions(-)

--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -3898,10 +3898,6 @@ static int hpsa_kdump_hard_reset_control

/* 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 */
@@ -3949,11 +3945,6 @@ static int hpsa_kdump_hard_reset_control
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)
@@ -4448,6 +4439,23 @@ static int hpsa_init_reset_devices(struc
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);

@@ -4456,10 +4464,11 @@ static int hpsa_init_reset_devices(struc
* "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");
@@ -4470,7 +4479,11 @@ static int hpsa_init_reset_devices(struc
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)
@@ -4613,6 +4626,7 @@ static void hpsa_undo_allocations_after_
iounmap(h->transtable);
if (h->cfgtable)
iounmap(h->cfgtable);
+ pci_disable_device(h->pdev);
pci_release_regions(h->pdev);
kfree(h);
}