fb: Yet another band-aid for fixing lockdep mess
I've still got lockdep warnings even after Alan's patch, and it seems that
yet more band aids are required to paper over similar paths for
unbind_con_driver() and unregister_con_driver(). After this hack, lockdep
warnings are finally gone.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: stable <stable@vger.kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index c076af0..457c41f 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -3135,6 +3135,18 @@
*/
int unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
{
+ int retval;
+
+ console_lock();
+ retval = do_unbind_con_driver(csw, first, last, deflt);
+ console_unlock();
+ return retval;
+}
+EXPORT_SYMBOL(unbind_con_driver);
+
+/* unlocked version of unbind_con_driver() */
+int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
+{
struct module *owner = csw->owner;
const struct consw *defcsw = NULL;
struct con_driver *con_driver = NULL, *con_back = NULL;
@@ -3143,7 +3155,7 @@
if (!try_module_get(owner))
return -ENODEV;
- console_lock();
+ WARN_CONSOLE_UNLOCKED();
/* check if driver is registered and if it is unbindable */
for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
@@ -3156,10 +3168,8 @@
}
}
- if (retval) {
- console_unlock();
+ if (retval)
goto err;
- }
retval = -ENODEV;
@@ -3175,15 +3185,11 @@
}
}
- if (retval) {
- console_unlock();
+ if (retval)
goto err;
- }
- if (!con_is_bound(csw)) {
- console_unlock();
+ if (!con_is_bound(csw))
goto err;
- }
first = max(first, con_driver->first);
last = min(last, con_driver->last);
@@ -3212,13 +3218,12 @@
/* ignore return value, binding should not fail */
do_bind_con_driver(defcsw, first, last, deflt);
- console_unlock();
err:
module_put(owner);
return retval;
}
-EXPORT_SYMBOL(unbind_con_driver);
+EXPORT_SYMBOL_GPL(do_unbind_con_driver);
static int vt_bind(struct con_driver *con)
{
@@ -3605,9 +3610,18 @@
*/
int unregister_con_driver(const struct consw *csw)
{
- int i, retval = -ENODEV;
+ int retval;
console_lock();
+ retval = do_unregister_con_driver(csw);
+ console_unlock();
+ return retval;
+}
+EXPORT_SYMBOL(unregister_con_driver);
+
+int do_unregister_con_driver(const struct consw *csw)
+{
+ int i, retval = -ENODEV;
/* cannot unregister a bound driver */
if (con_is_bound(csw))
@@ -3633,10 +3647,9 @@
}
}
err:
- console_unlock();
return retval;
}
-EXPORT_SYMBOL(unregister_con_driver);
+EXPORT_SYMBOL_GPL(do_unregister_con_driver);
/*
* If we support more console drivers, this function is used
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 4bd7820..2aef9ca 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -3004,7 +3004,7 @@
{
int ret;
- ret = unbind_con_driver(&fb_con, first_fb_vc, last_fb_vc,
+ ret = do_unbind_con_driver(&fb_con, first_fb_vc, last_fb_vc,
fbcon_is_default);
if (!ret)
@@ -3077,7 +3077,7 @@
primary_device = -1;
if (!num_registered_fb)
- unregister_con_driver(&fb_con);
+ do_unregister_con_driver(&fb_con);
return 0;
}
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index d8d9831..070b9a1 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1668,8 +1668,10 @@
if (!lock_fb_info(fb_info))
return -ENODEV;
+ console_lock();
event.info = fb_info;
ret = fb_notifier_call_chain(FB_EVENT_FB_UNBIND, &event);
+ console_unlock();
unlock_fb_info(fb_info);
if (ret)
@@ -1684,7 +1686,9 @@
num_registered_fb--;
fb_cleanup_device(fb_info);
event.info = fb_info;
+ console_lock();
fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
+ console_unlock();
/* this may free fb info */
put_fb_info(fb_info);
diff --git a/include/linux/console.h b/include/linux/console.h
index 4ef4307..47b858c 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -77,6 +77,7 @@
int con_is_bound(const struct consw *csw);
int register_con_driver(const struct consw *csw, int first, int last);
int unregister_con_driver(const struct consw *csw);
+int do_unregister_con_driver(const struct consw *csw);
int take_over_console(const struct consw *sw, int first, int last, int deflt);
int do_take_over_console(const struct consw *sw, int first, int last, int deflt);
void give_up_console(const struct consw *sw);
diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
index 50ae7d0..dbbc6bf 100644
--- a/include/linux/vt_kern.h
+++ b/include/linux/vt_kern.h
@@ -130,6 +130,8 @@
int vt_waitactive(int n);
void change_console(struct vc_data *new_vc);
void reset_vc(struct vc_data *vc);
+extern int do_unbind_con_driver(const struct consw *csw, int first, int last,
+ int deflt);
extern int unbind_con_driver(const struct consw *csw, int first, int last,
int deflt);
int vty_init(const struct file_operations *console_fops);