[PATCH] Video: fb, add true ref_count atomicity

Some of fb drivers uses atomic_t in bad manner, since there are still some
race-prone gaps.  Use mutexes to protect open/close code sections with
ref_count testing and finally use simple uint.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Denis Oliver Kropp <dok@directfb.org>
Cc: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/video/neomagic.h b/include/video/neomagic.h
index 78b1f15a538f..a9e118a1cd16 100644
--- a/include/video/neomagic.h
+++ b/include/video/neomagic.h
@@ -140,7 +140,8 @@ typedef volatile struct {
 
 struct neofb_par {
         struct vgastate state;
-        atomic_t ref_count;
+        struct mutex open_lock;
+        unsigned int ref_count;
 
         unsigned char MiscOutReg;       /* Misc */
         unsigned char CRTC[25];         /* Crtc Controller */