PTI driver cleanup path bug fix

This patch addresses some remove issues in the pti_pci_remove() and _exit()
routines in the pti driver that were uncovered in module load and unload
stress testing:

1. a double kfree() issue between the _remove() and _exit() routine
2. pci_release_region() in _remove() that was not really releasing
   the region from the _probe() call, thereby causing a BUSY error
   on the next load of the driver module.
3. 2. uncovered a corner-case issue in which misc_register() wasn't
   called in _probe() before an error-cleanup routine was called which
   was causing an issue in the _exit() routine.
4. A couple unregister_driver() calls added to exit().

Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>

1 files changed, 19 insertions, 18 deletions

diff --git a/drivers/misc/pti.c b/drivers/misc/pti.c
index 83dda4d64e9..f7a56be91cb 100644
--- a/drivers/misc/pti.c
+++ b/drivers/misc/pti.c
@@ -366,7 +366,7 @@ static void __devexit pti_pci_remove(struct pci_dev *pdev)
 		pci_iounmap(pdev, drv_data->pti_ioaddr);
 		pci_set_drvdata(pdev, NULL);
 		kfree(drv_data);
-		pci_release_region(pdev, 0);
+		pci_release_region(pdev, 1);
 		pci_disable_device(pdev);
 	}
 }
@@ -720,6 +720,15 @@ static int __devinit pti_pci_probe(struct pci_dev *pdev,
 	dev_dbg(&pdev->dev, "%s %s(%d): PTI PCI ID %04x:%04x\n", __FILE__,
 			__func__, __LINE__, pdev->vendor, pdev->device);
 
+       retval = misc_register(&pti_char_driver);
+	if (retval) {
+		pr_err("%s(%d): CHAR registration failed of pti driver\n",
+			__func__, __LINE__);
+		pr_err("%s(%d): Error value returned: %d\n",
+			__func__, __LINE__, retval);
+		return retval;
+	}
+
 	retval = pci_enable_device(pdev);
 	if (retval != 0) {
 		dev_err(&pdev->dev,
@@ -769,15 +778,6 @@ static int __devinit pti_pci_probe(struct pci_dev *pdev,
 
 	register_console(&pti_console);
 
-	retval = misc_register(&pti_char_driver);
-	if (retval) {
-		pr_err("%s(%d): CHAR registration failed of pti driver\n",
-			__func__, __LINE__);
-		pr_err("%s(%d): Error value returned: %d\n",
-			__func__, __LINE__, retval);
-		return retval;
-	}
-
 	return retval;
 }
 
@@ -860,27 +860,28 @@ static void __exit pti_exit(void)
 {
 	int retval;
 
-	retval = misc_deregister(&pti_char_driver);
+	tty_unregister_device(pti_tty_driver, 0);
+	tty_unregister_device(pti_tty_driver, 1);
+
+	retval = tty_unregister_driver(pti_tty_driver);
 	if (retval) {
-		pr_err("%s(%d): CHAR unregistration failed of pti driver\n",
+		pr_err("%s(%d): TTY unregistration failed of pti driver\n",
 			__func__, __LINE__);
 		pr_err("%s(%d): Error value returned: %d\n",
 			__func__, __LINE__, retval);
 	}
 
-	tty_unregister_device(pti_tty_driver, 0);
-	tty_unregister_device(pti_tty_driver, 1);
+	pci_unregister_driver(&pti_pci_driver);
 
-	retval = tty_unregister_driver(pti_tty_driver);
+	retval = misc_deregister(&pti_char_driver);
 	if (retval) {
-		pr_err("%s(%d): TTY unregistration failed of pti driver\n",
+		pr_err("%s(%d): CHAR unregistration failed of pti driver\n",
 			__func__, __LINE__);
 		pr_err("%s(%d): Error value returned: %d\n",
 			__func__, __LINE__, retval);
 	}
 
-	kfree(drv_data);
-
+	unregister_console(&pti_console);
 	return;
 }