From 537a1bf059fa312355696fa6db80726e655e7f17 Mon Sep 17 00:00:00 2001 From: Krzysztof Helt Date: Tue, 30 Jun 2009 11:41:29 -0700 Subject: 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 Cc: Peter Zijlstra Cc: "Rafael J. Wysocki" Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/pxafb.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/video/pxafb.c') diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c index 0889d50c328..6506117c134 100644 --- a/drivers/video/pxafb.c +++ b/drivers/video/pxafb.c @@ -815,8 +815,10 @@ static int overlayfb_map_video_memory(struct pxafb_layer *ofb) ofb->video_mem_phys = virt_to_phys(ofb->video_mem); ofb->video_mem_size = size; + mutex_lock(&ofb->fb.mm_lock); ofb->fb.fix.smem_start = ofb->video_mem_phys; ofb->fb.fix.smem_len = ofb->fb.fix.line_length * var->yres_virtual; + mutex_unlock(&ofb->fb.mm_lock); ofb->fb.screen_base = ofb->video_mem; return 0; } -- cgit v1.2.3-70-g09d2