Mutexes should not be acquired in interrupt context. While the trylock fastpath is arguably safe on all implementations, the slowpath unlock path definitely isn't.
Signed-off-by: Maarten Lankhorst maarten.lankhorst@canonical.com --- drivers/gpu/drm/ast/ast_fb.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c index fbc0823..7b33e14 100644 --- a/drivers/gpu/drm/ast/ast_fb.c +++ b/drivers/gpu/drm/ast/ast_fb.c @@ -51,7 +51,7 @@ static void ast_dirty_update(struct ast_fbdev *afbdev, struct ast_bo *bo; int src_offset, dst_offset; int bpp = (afbdev->afb.base.bits_per_pixel + 7)/8; - int ret; + int ret = -EBUSY; bool unmap = false; bool store_for_later = false; int x2, y2; @@ -65,7 +65,8 @@ static void ast_dirty_update(struct ast_fbdev *afbdev, * then the BO is being moved and we should * store up the damage until later. */ - ret = ast_bo_reserve(bo, true); + if (!in_interrupt()) + ret = ast_bo_reserve(bo, true); if (ret) { if (ret != -EBUSY) return;