[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/drivers/video/i810/i810.h b/drivers/video/i810/i810.h
index 579195c2bea3..aa65ffce915b 100644
--- a/drivers/video/i810/i810.h
+++ b/drivers/video/i810/i810.h
@@ -264,7 +264,8 @@ struct i810fb_par {
         struct heap_data         cursor_heap;
         struct vgastate          state;
         struct i810fb_i2c_chan   chan[3];
-        atomic_t                 use_count;
+        struct mutex             open_lock;
+        unsigned int             use_count;
         u32 pseudo_palette[17];
         unsigned long mmio_start_phys;
         u8 __iomem *mmio_start_virtual;