diff options
| author | Krzysztof Helt <krzysztof.h1@wp.pl> | 2009-06-30 11:41:29 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-30 18:56:00 -0700 |
| commit | 537a1bf059fa312355696fa6db80726e655e7f17 (patch) | |
| tree | 4f5b3c6917311cfefad21eaf3dd92978334282de /drivers/video/omap | |
| parent | 70d6027ff2bc8bab180273b77e7ab3e8a62cca51 (diff) | |
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 'drivers/video/omap')
| -rw-r--r-- | drivers/video/omap/omapfb_main.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/video/omap/omapfb_main.c b/drivers/video/omap/omapfb_main.c index 060d72fe57c..4ea99bfc37b 100644 --- a/drivers/video/omap/omapfb_main.c +++ b/drivers/video/omap/omapfb_main.c @@ -393,8 +393,10 @@ static void set_fb_fix(struct fb_info *fbi) rg = &plane->fbdev->mem_desc.region[plane->idx]; fbi->screen_base = rg->vaddr; + mutex_lock(&fbi->mm_lock); fix->smem_start = rg->paddr; fix->smem_len = rg->size; + mutex_unlock(&fbi->mm_lock); fix->type = FB_TYPE_PACKED_PIXELS; bpp = var->bits_per_pixel; @@ -886,8 +888,10 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi) * plane memory is dealloce'd, the other * screen parameters in var / fix are invalid. */ + mutex_lock(&fbi->mm_lock); fbi->fix.smem_start = 0; fbi->fix.smem_len = 0; + mutex_unlock(&fbi->mm_lock); } } } |