dtlk: fix error checks in module_init()
This patch fixes two things in module_init.
- fix register_chrdev() error check
Currently dtlk doesn't check register_chrdev() failure correctly.
register_chrdev() returns a errno on failure.
- check probe failure
dtlk ignores probe failure and allows the module loading without
such device. I got "Trying to free nonexistent resource" message
by release_region() when unloading module without device.
[akpm@linux-foundation.org: fix error code return]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Chris Pallotta <chris@allmedia.com>
Cc: Jim Van Zandt <jrv@vanzandt.mv.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/dtlk.c b/drivers/char/dtlk.c
index 9695f88..abde6dd 100644
--- a/drivers/char/dtlk.c
+++ b/drivers/char/dtlk.c
@@ -324,16 +324,22 @@
static int __init dtlk_init(void)
{
+ int err;
+
dtlk_port_lpc = 0;
dtlk_port_tts = 0;
dtlk_busy = 0;
dtlk_major = register_chrdev(0, "dtlk", &dtlk_fops);
- if (dtlk_major == 0) {
+ if (dtlk_major < 0) {
printk(KERN_ERR "DoubleTalk PC - cannot register device\n");
- return 0;
+ return dtlk_major;
}
- if (dtlk_dev_probe() == 0)
- printk(", MAJOR %d\n", dtlk_major);
+ err = dtlk_dev_probe();
+ if (err) {
+ unregister_chrdev(dtlk_major, "dtlk");
+ return err;
+ }
+ printk(", MAJOR %d\n", dtlk_major);
init_waitqueue_head(&dtlk_process_list);