[PATCH] rio_linux.c misc_register patch

From:  Chris Wilson <chris@qwirx.com>

  This function did check misc_register's return code, but made no effort to
  clean up if it failed, leaving a large amount of potential crud lying
  around. I moved the registration to the start of the function, so that the
  cleanup is trivial, and made sure the device gets unregistered in the
  cases where it would not have been registered at all before.

drivers/char/rio/rio_linux.c

@@ -1139,7 +1139,6 @@ static int __init rio_init(void)
   struct vpd_prom *vpdp;
   int okboard;
 
-
 #ifdef CONFIG_PCI
 #ifndef TWO_ZERO
   struct pci_dev *pdev = NULL;
@@ -1161,8 +1160,16 @@ static int __init rio_init(void)
     rio_debug=-1;
   }
 
+  if (misc_register(&rio_fw_device) < 0) {
+    printk(KERN_ERR "RIO: Unable to register firmware loader driver.\n");
+    return -EIO;
+  }
+
   retval = rio_init_datastructures ();
-  if (retval < 0) return retval;
+  if (retval < 0) {
+    misc_deregister(&rio_fw_device);
+    return retval;
+  }
 
 #ifdef CONFIG_PCI
   if (pci_present ()) {
@@ -1400,12 +1407,10 @@ static int __init rio_init(void)
 
   if (found) {
     rio_dprintk (RIO_DEBUG_INIT, "rio: total of %d boards detected.\n", found);
-
-    if (misc_register(&rio_fw_device) < 0) {
-      printk(KERN_ERR "RIO: Unable to register firmware loader driver.\n");
-      return -EIO;
-    }
     rio_init_drivers ();
+  } else {
+    /* deregister the misc device we created earlier */
+    misc_deregister(&rio_fw_device);
   }
 
   func_exit();