drm/sti: do not check hw scaling if mode is not set

Fix a division by 0 case : in some cases, when the HQVDP plane is being
disabled atomic_check() is called with "mode->clock = 0".
In that case, do not check for scaling capabilities.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Acked-by: Vincent Abriou <vincent.abriou@st.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/gpu/drm/sti/sti_hqvdp.c b/drivers/gpu/drm/sti/sti_hqvdp.c
index 4376fd8a8e52..66f843148ef7 100644
--- a/drivers/gpu/drm/sti/sti_hqvdp.c
+++ b/drivers/gpu/drm/sti/sti_hqvdp.c
@@ -1037,9 +1037,9 @@ static int sti_hqvdp_atomic_check(struct drm_plane *drm_plane,
         src_w = state->src_w >> 16;
         src_h = state->src_h >> 16;
 
-        if (!sti_hqvdp_check_hw_scaling(hqvdp, mode,
-                                        src_w, src_h,
-                                        dst_w, dst_h)) {
+        if (mode->clock && !sti_hqvdp_check_hw_scaling(hqvdp, mode,
+                                                       src_w, src_h,
+                                                       dst_w, dst_h)) {
                 DRM_ERROR("Scaling beyond HW capabilities\n");
                 return -EINVAL;
         }