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authorJean Delvare <jdelvare@suse.de>2014-02-25 09:43:13 +0100
committerBorislav Petkov <bp@suse.de>2014-02-25 09:43:13 +0100
commit75135da0d68419ef8a925f4c1d5f63d8046e314d (patch)
treedb9f21d3b0131bcd7c23c510852ad4143a44f1a4 /drivers/edac/i7300_edac.c
parentc0f5eeed0f4cef4f05b74883a7160e7edde58b6a (diff)
downloadlinux-75135da0d68419ef8a925f4c1d5f63d8046e314d.tar.gz
i7300_edac: Fix device reference count
pci_get_device() decrements the reference count of "from" (last
argument) so when we break off the loop successfully we have only one
device reference - and we don't know which device we have. If we want
a reference to each device, we must take them explicitly and let
the pci_get_device() walk complete to avoid duplicate references.

This is serious, as over-putting device references will cause
the device to eventually disappear. Without this fix, the kernel
crashes after a few insmod/rmmod cycles.

Tested on an Intel S7000FC4UR system with a 7300 chipset.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Link: http://lkml.kernel.org/r/20140224111656.09bbb7ed@endymion.delvare
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: stable@vger.kernel.org
Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'drivers/edac/i7300_edac.c')
-rw-r--r--drivers/edac/i7300_edac.c38
1 files changed, 20 insertions, 18 deletions
diff --git a/drivers/edac/i7300_edac.c b/drivers/edac/i7300_edac.c
index d63f4798f7d0..57e96a3350f0 100644
--- a/drivers/edac/i7300_edac.c
+++ b/drivers/edac/i7300_edac.c
@@ -943,33 +943,35 @@ static int i7300_get_devices(struct mem_ctl_info *mci)
 
 	/* Attempt to 'get' the MCH register we want */
 	pdev = NULL;
-	while (!pvt->pci_dev_16_1_fsb_addr_map ||
-	       !pvt->pci_dev_16_2_fsb_err_regs) {
-		pdev = pci_get_device(PCI_VENDOR_ID_INTEL,
-				      PCI_DEVICE_ID_INTEL_I7300_MCH_ERR, pdev);
-		if (!pdev) {
-			/* End of list, leave */
-			i7300_printk(KERN_ERR,
-				"'system address,Process Bus' "
-				"device not found:"
-				"vendor 0x%x device 0x%x ERR funcs "
-				"(broken BIOS?)\n",
-				PCI_VENDOR_ID_INTEL,
-				PCI_DEVICE_ID_INTEL_I7300_MCH_ERR);
-			goto error;
-		}
-
+	while ((pdev = pci_get_device(PCI_VENDOR_ID_INTEL,
+				      PCI_DEVICE_ID_INTEL_I7300_MCH_ERR,
+				      pdev))) {
 		/* Store device 16 funcs 1 and 2 */
 		switch (PCI_FUNC(pdev->devfn)) {
 		case 1:
-			pvt->pci_dev_16_1_fsb_addr_map = pdev;
+			if (!pvt->pci_dev_16_1_fsb_addr_map)
+				pvt->pci_dev_16_1_fsb_addr_map =
+							pci_dev_get(pdev);
 			break;
 		case 2:
-			pvt->pci_dev_16_2_fsb_err_regs = pdev;
+			if (!pvt->pci_dev_16_2_fsb_err_regs)
+				pvt->pci_dev_16_2_fsb_err_regs =
+							pci_dev_get(pdev);
 			break;
 		}
 	}
 
+	if (!pvt->pci_dev_16_1_fsb_addr_map ||
+	    !pvt->pci_dev_16_2_fsb_err_regs) {
+		/* At least one device was not found */
+		i7300_printk(KERN_ERR,
+			"'system address,Process Bus' device not found:"
+			"vendor 0x%x device 0x%x ERR funcs (broken BIOS?)\n",
+			PCI_VENDOR_ID_INTEL,
+			PCI_DEVICE_ID_INTEL_I7300_MCH_ERR);
+		goto error;
+	}
+
 	edac_dbg(1, "System Address, processor bus- PCI Bus ID: %s  %x:%x\n",
 		 pci_name(pvt->pci_dev_16_0_fsb_ctlr),
 		 pvt->pci_dev_16_0_fsb_ctlr->vendor,