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/matrox/matroxfb_crtc2.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/video/matrox/matroxfb_crtc2.c') diff --git a/drivers/video/matrox/matroxfb_crtc2.c b/drivers/video/matrox/matroxfb_crtc2.c index 7ac4c5f6145d..909e10a11898 100644 --- a/drivers/video/matrox/matroxfb_crtc2.c +++ b/drivers/video/matrox/matroxfb_crtc2.c @@ -289,13 +289,16 @@ static int matroxfb_dh_release(struct fb_info* info, int user) { #undef m2info } -static void matroxfb_dh_init_fix(struct matroxfb_dh_fb_info *m2info) { +static void matroxfb_dh_init_fix(struct matroxfb_dh_fb_info *m2info) +{ struct fb_fix_screeninfo *fix = &m2info->fbcon.fix; strcpy(fix->id, "MATROX DH"); + mutex_lock(&m2info->fbcon.mm_lock); fix->smem_start = m2info->video.base; fix->smem_len = m2info->video.len_usable; + mutex_unlock(&m2info->fbcon.mm_lock); fix->ypanstep = 1; fix->ywrapstep = 0; fix->xpanstep = 8; /* TBD */ -- cgit v1.2.2