drm/i915/skl: don't fail colorkey + scaler request

There is a mplayer video failure reported with xv.
This is because there is a request to do both plane scaling
and colorkey. Because skl hw doesn't support plane scaling
and colorkey at the same time, request is failed which is expected
behavior.

To make xv operate, this patch allows colorkey continue to work
without using scaler. Then behavior would be similar to platforms
without plane scaler support.
Signed-off-by: Chandra Konduru <chandra.konduru@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90449
[danvet: change can_scale to bool as requested by Ville.]
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -4502,9 +4502,10 @@ skl_update_scaler_users(
 	}
 
 	/* check colorkey */
-	if (intel_plane && intel_plane->ckey.flags != I915_SET_COLORKEY_NONE) {
-		DRM_DEBUG_KMS("PLANE:%d scaling with color key not allowed",
-			intel_plane->base.base.id);
+	if (WARN_ON(intel_plane &&
+		intel_plane->ckey.flags != I915_SET_COLORKEY_NONE)) {
+		DRM_DEBUG_KMS("PLANE:%d scaling %ux%u->%ux%u not allowed with colorkey",
+			intel_plane->base.base.id, src_w, src_h, dst_w, dst_h);
 		return -EINVAL;
 	}
 
@@ -13261,8 +13262,11 @@ intel_check_primary_plane(struct drm_plane *plane,
 		intel_atomic_get_crtc_state(state->base.state, intel_crtc) : NULL;
 
 	if (INTEL_INFO(dev)->gen >= 9) {
+		/* use scaler when colorkey is not required */
+		if (to_intel_plane(plane)->ckey.flags == I915_SET_COLORKEY_NONE) {
 			min_scale = 1;
 			max_scale = skl_max_scale(intel_crtc, crtc_state);
+		}
 		can_position = true;
 	}
 

drivers/gpu/drm/i915/intel_sprite.c

@@ -770,6 +770,7 @@ intel_check_sprite_plane(struct drm_plane *plane,
 	const struct drm_rect *clip = &state->clip;
 	int hscale, vscale;
 	int max_scale, min_scale;
+	bool can_scale;
 	int pixel_size;
 	int ret;
 
@@ -794,18 +795,29 @@ intel_check_sprite_plane(struct drm_plane *plane,
 		return -EINVAL;
 	}
 
+	/* setup can_scale, min_scale, max_scale */
+	if (INTEL_INFO(dev)->gen >= 9) {
+		/* use scaler when colorkey is not required */
+		if (intel_plane->ckey.flags == I915_SET_COLORKEY_NONE) {
+			can_scale = 1;
+			min_scale = 1;
+			max_scale = skl_max_scale(intel_crtc, crtc_state);
+		} else {
+			can_scale = 0;
+			min_scale = DRM_PLANE_HELPER_NO_SCALING;
+			max_scale = DRM_PLANE_HELPER_NO_SCALING;
+		}
+	} else {
+		can_scale = intel_plane->can_scale;
+		max_scale = intel_plane->max_downscale << 16;
+		min_scale = intel_plane->can_scale ? 1 : (1 << 16);
+	}
+
 	/*
 	 * FIXME the following code does a bunch of fuzzy adjustments to the
 	 * coordinates and sizes. We probably need some way to decide whether
 	 * more strict checking should be done instead.
 	 */
-	max_scale = intel_plane->max_downscale << 16;
-	min_scale = intel_plane->can_scale ? 1 : (1 << 16);
-
-	if (INTEL_INFO(dev)->gen >= 9) {
-		min_scale = 1;
-		max_scale = skl_max_scale(intel_crtc, crtc_state);
-	}
 
 	drm_rect_rotate(src, fb->width << 16, fb->height << 16,
 			state->base.rotation);
@@ -876,7 +888,7 @@ intel_check_sprite_plane(struct drm_plane *plane,
 			 * Must keep src and dst the
 			 * same if we can't scale.
 			 */
-			if (!intel_plane->can_scale)
+			if (!can_scale)
 				crtc_w &= ~1;
 
 			if (crtc_w == 0)
@@ -888,7 +900,7 @@ intel_check_sprite_plane(struct drm_plane *plane,
 	if (state->visible && (src_w != crtc_w || src_h != crtc_h)) {
 		unsigned int width_bytes;
 
-		WARN_ON(!intel_plane->can_scale);
+		WARN_ON(!can_scale);
 
 		/* FIXME interlacing min height is 6 */