[PATCH] epca: prevent panic on tty_register_driver() failure

Make epca fail on initialization failure instead of panic.

Cc: "Digi International, Inc" <Eng.Linux@digi.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Alan Cox <alan@redhat.com>
Acked-by: Scott Kilau <scottk@digi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 23 insertions, 9 deletions

diff --git a/drivers/char/epca.c b/drivers/char/epca.c
index c3f95583a120..706733c0b36a 100644
--- a/drivers/char/epca.c
+++ b/drivers/char/epca.c
@@ -1157,6 +1157,7 @@ static int __init pc_init(void)
         int crd;
         struct board_info *bd;
         unsigned char board_id = 0;
+        int err = -ENOMEM;
 
         int pci_boards_found, pci_count;
 
@@ -1164,13 +1165,11 @@ static int __init pc_init(void)
 
         pc_driver = alloc_tty_driver(MAX_ALLOC);
         if (!pc_driver)
-                return -ENOMEM;
+                goto out1;
 
         pc_info = alloc_tty_driver(MAX_ALLOC);
-        if (!pc_info) {
-                put_tty_driver(pc_driver);
-                return -ENOMEM;
-        }
+        if (!pc_info)
+                goto out2;
 
         /* -----------------------------------------------------------------------
                 If epca_setup has not been ran by LILO set num_cards to defaults; copy
@@ -1370,11 +1369,17 @@ static int __init pc_init(void)
 
         } /* End for each card */
 
-        if (tty_register_driver(pc_driver))
-                panic("Couldn't register Digi PC/ driver");
+        err = tty_register_driver(pc_driver);
+        if (err) {
+                printk(KERN_ERR "Couldn't register Digi PC/ driver");
+                goto out3;
+        }
 
-        if (tty_register_driver(pc_info))
-                panic("Couldn't register Digi PC/ info ");
+        err = tty_register_driver(pc_info);
+        if (err) {
+                printk(KERN_ERR "Couldn't register Digi PC/ info ");
+                goto out4;
+        }
 
         /* -------------------------------------------------------------------
            Start up the poller to check for events on all enabled boards
@@ -1385,6 +1390,15 @@ static int __init pc_init(void)
         mod_timer(&epca_timer, jiffies + HZ/25);
         return 0;
 
+out4:
+        tty_unregister_driver(pc_driver);
+out3:
+        put_tty_driver(pc_info);
+out2:
+        put_tty_driver(pc_driver);
+out1:
+        return err;
+
 } /* End pc_init */
 
 /* ------------------ Begin post_fep_init  ---------------------- */