[PATCH AUTOSEL 4.14 32/89] fbdev/core: Disable console-lock warnings when fb.lockless_register_fb is set

[Sasha Levin]

From: Thomas Zimmermann <tzimmerm...@suse.de>

[ Upstream commit 3f2ce54284a60500eb6dca1dca6fd615df8f9aa3 ]

If the console is unlocked during registration, the console subsystem
generates significant amounts of warnings, which obfuscate actual
debugging messages. Setting ignore_console_lock_warning while debugging
console registration avoid the noise.

v3:
        - manipulate ignore_console_lock_warning with atomic_{inc,dec}
v2:
        - restore ignore_console_lock_warning if lock_fb_info() fails

Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
Acked-by: Hans de Goede <hdego...@redhat.com>
Reviewed-by: Petr Mladek <pmla...@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com>
Cc: Steven Rostedt (VMware) <rost...@goodmis.org>
Cc: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnier...@samsung.com>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
---
 drivers/video/fbdev/core/fbmem.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index f741ba8df01b..cd659f862d74 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1703,17 +1703,22 @@ static int do_register_framebuffer(struct fb_info 
*fb_info)
        event.info = fb_info;
        if (!lockless_register_fb)
                console_lock();
+       else
+               atomic_inc(&ignore_console_lock_warning);
        if (!lock_fb_info(fb_info)) {
-               if (!lockless_register_fb)
-                       console_unlock();
-               return -ENODEV;
+               ret = -ENODEV;
+               goto unlock_console;
        }
+       ret = 0;
 
        fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
        unlock_fb_info(fb_info);
+unlock_console:
        if (!lockless_register_fb)
                console_unlock();
-       return 0;
+       else
+               atomic_dec(&ignore_console_lock_warning);
+       return ret;
 }
 
 static int do_unregister_framebuffer(struct fb_info *fb_info)
-- 
2.17.1