diff options
| author | Krzysztof Helt <krzysztof.h1@wp.pl> | 2009-06-30 20:41:29 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-07-01 03:56:00 +0200 |
| commit | 537a1bf059fa312355696fa6db80726e655e7f17 (patch) | |
| tree | 4f5b3c6917311cfefad21eaf3dd92978334282de /include | |
| parent | spi: add spi_master flag word (diff) | |
| download | linux-537a1bf059fa312355696fa6db80726e655e7f17.tar.xz linux-537a1bf059fa312355696fa6db80726e655e7f17.zip | |
fbdev: add mutex for fb_mmap locking
Add a mutex to avoid a circular locking problem between the mm layer
semaphore and fbdev ioctl mutex through the fb_mmap() call.
Also, add mutex to all places where smem_start and smem_len fields change
so the mutex inside the fb_mmap() is actually used. Changing of these
fields before calling the framebuffer_register() are not mutexed.
This is 2.6.31 material. It removes one lockdep (fb_mmap() and
register_framebuffer()) but there is still another one (fb_release() and
register_framebuffer()). It also cleans up handling of the smem_start and
smem_len fields used by mutexed section of the fb_mmap().
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/fb.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/fb.h b/include/linux/fb.h index dd68358996b7..f847df9e99b6 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -819,6 +819,7 @@ struct fb_info { int node; int flags; struct mutex lock; /* Lock for open/release/ioctl funcs */ + struct mutex mm_lock; /* Lock for fb_mmap and smem_* fields */ struct fb_var_screeninfo var; /* Current var */ struct fb_fix_screeninfo fix; /* Current fix */ struct fb_monspecs monspecs; /* Current Monitor specs */ |