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 c076af0b300bc805934087f498bf8f443d85cf64..457c41fe7eb955041d78553df0a01ad6155fe4a7 100644 (file)
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -3134,6 +3134,18 @@ static int con_is_graphics(const struct consw *csw, int first, int last)
  * or 0 on success.
  */
 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;
@@ -3143,7 +3155,7 @@ int unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
        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 @@ int unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
                }
        }
 
-       if (retval) {
-               console_unlock();
+       if (retval)
                goto err;
-       }
 
        retval = -ENODEV;
 
@@ -3175,15 +3185,11 @@ int unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
                }
        }
 
-       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 @@ int unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
 
        /* 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 @@ EXPORT_SYMBOL(register_con_driver);
  */
 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 @@ int unregister_con_driver(const struct consw *csw)
                }
        }
 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 4bd7820cf4d087cf93a3690698605f2c5fe36391..2aef9cac4d18feff28ff9766f42176b1c0e53060 100644 (file)
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -3004,7 +3004,7 @@ static int fbcon_unbind(void)
 {
        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 @@ static int fbcon_fb_unregistered(struct fb_info *info)
                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 d8d9831b3fdbd0677595241babdb2dd8e927a96e..070b9a13d8920ba9929e2a49c466d580da1cac2c 100644 (file)
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1668,8 +1668,10 @@ static int do_unregister_framebuffer(struct fb_info *fb_info)
 
        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 @@ static int do_unregister_framebuffer(struct fb_info *fb_info)
        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 4ef4307dfb82329240beab54cf7849dd690eb6a9..47b858cffc478ce21bd4fc89bd0ac740dfa5cb50 100644 (file)
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -77,6 +77,7 @@ extern const struct consw prom_con;   /* SPARC PROM console */
 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 50ae7d0c279ed2ddbdb626aa67dcc9abad619781..dbbc6bfee71fdf75b9184d7d762c45784d2a0fa1 100644 (file)
--- a/include/linux/vt_kern.h
+++ b/include/linux/vt_kern.h
@@ -130,6 +130,8 @@ void vt_event_post(unsigned int event, unsigned int old, unsigned int new);
 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);