drm/sti: enable gdp pixel clock in atomic_update

Set gdp pix clock rate and parent in atomic_check function and enable
it in the atomic_update only the first time.
Signed-off-by: Vincent Abriou <vincent.abriou@st.com>

drivers/gpu/drm/sti/sti_gdp.c

@@ -610,7 +610,6 @@ static int sti_gdp_atomic_check(struct drm_plane *drm_plane,
 	struct sti_plane *plane = to_sti_plane(drm_plane);
 	struct sti_gdp *gdp = to_sti_gdp(plane);
 	struct drm_crtc *crtc = state->crtc;
-	struct sti_compositor *compo = dev_get_drvdata(gdp->dev);
 	struct drm_framebuffer *fb =  state->fb;
 	struct drm_crtc_state *crtc_state;
 	struct sti_mixer *mixer;
@@ -648,45 +647,30 @@ static int sti_gdp_atomic_check(struct drm_plane *drm_plane,
 		return -EINVAL;
 	}
 
-	if (!gdp->vtg) {
-		/* Register gdp callback */
-		gdp->vtg = compo->vtg[mixer->id];
-		if (sti_vtg_register_client(gdp->vtg,
-					    &gdp->vtg_field_nb, crtc)) {
-			DRM_ERROR("Cannot register VTG notifier\n");
+	/* Set gdp clock */
+	if (gdp->clk_pix) {
+		struct clk *clkp;
+		int rate = mode->clock * 1000;
+		int res;
+
+		/*
+		 * According to the mixer used, the gdp pixel clock
+		 * should have a different parent clock.
+		 */
+		if (mixer->id == STI_MIXER_MAIN)
+			clkp = gdp->clk_main_parent;
+		else
+			clkp = gdp->clk_aux_parent;
+
+		if (clkp)
+			clk_set_parent(gdp->clk_pix, clkp);
+
+		res = clk_set_rate(gdp->clk_pix, rate);
+		if (res < 0) {
+			DRM_ERROR("Cannot set rate (%dHz) for gdp\n",
+				  rate);
 			return -EINVAL;
 		}
-
-		/* Set and enable gdp clock */
-		if (gdp->clk_pix) {
-			struct clk *clkp;
-			int rate = mode->clock * 1000;
-			int res;
-
-			/*
-			 * According to the mixer used, the gdp pixel clock
-			 * should have a different parent clock.
-			 */
-			if (mixer->id == STI_MIXER_MAIN)
-				clkp = gdp->clk_main_parent;
-			else
-				clkp = gdp->clk_aux_parent;
-
-			if (clkp)
-				clk_set_parent(gdp->clk_pix, clkp);
-
-			res = clk_set_rate(gdp->clk_pix, rate);
-			if (res < 0) {
-				DRM_ERROR("Cannot set rate (%dHz) for gdp\n",
-					  rate);
-				return -EINVAL;
-			}
-
-			if (clk_prepare_enable(gdp->clk_pix)) {
-				DRM_ERROR("Failed to prepare/enable gdp\n");
-				return -EINVAL;
-			}
-		}
 	}
 
 	DRM_DEBUG_KMS("CRTC:%d (%s) drm plane:%d (%s)\n",
@@ -724,6 +708,16 @@ static void sti_gdp_atomic_update(struct drm_plane *drm_plane,
 	if (!crtc || !fb)
 		return;
 
+	if (!gdp->vtg) {
+		struct sti_compositor *compo = dev_get_drvdata(gdp->dev);
+		struct sti_mixer *mixer = to_sti_mixer(crtc);
+
+		/* Register gdp callback */
+		gdp->vtg = compo->vtg[mixer->id];
+		sti_vtg_register_client(gdp->vtg, &gdp->vtg_field_nb, crtc);
+		clk_prepare_enable(gdp->clk_pix);
+	}
+
 	mode = &crtc->mode;
 	dst_x = state->crtc_x;
 	dst_y = state->crtc_y;