drm/vmwgfx: Try to fix plane clipping

Try to fix the code to actually clip the plane to the crtc bounds
instead of the user provided crtc coordinates (which would be a no-op
since those are exactly the coordinates before clipping).

Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171101182920.14386-4-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>

drivers/gpu/drm/vmwgfx/vmwgfx_kms.c

@@ -441,20 +441,23 @@ vmw_du_cursor_plane_atomic_update(struct drm_plane *plane,
 int vmw_du_primary_plane_atomic_check(struct drm_plane *plane,
 				      struct drm_plane_state *state)
 {
+	struct drm_crtc_state *crtc_state = NULL;
 	struct drm_framebuffer *new_fb = state->fb;
-	struct drm_rect clip = {
-		.x1 = state->crtc_x,
-		.y1 = state->crtc_y,
-		.x2 = state->crtc_x + state->crtc_w,
-		.y2 = state->crtc_y + state->crtc_h,
-	};
+	struct drm_rect clip = {};
 	int ret;
 
-	ret = drm_plane_helper_check_state(state, &clip,
-					    DRM_PLANE_HELPER_NO_SCALING,
-					    DRM_PLANE_HELPER_NO_SCALING,
-					    false, true);
+	if (state->crtc)
+		crtc_state = drm_atomic_get_new_crtc_state(state->state, state->crtc);
 
+	if (crtc_state && crtc_state->enable) {
+		clip.x2 = crtc_state->adjusted_mode.hdisplay;
+		clip.y2 = crtc_state->adjusted_mode.vdisplay;
+	}
+
+	ret = drm_plane_helper_check_state(state, &clip,
+					   DRM_PLANE_HELPER_NO_SCALING,
+					   DRM_PLANE_HELPER_NO_SCALING,
+					   false, true);
 
 	if (!ret && new_fb) {
 		struct drm_crtc *crtc = state->crtc;