1 files changed, 14 insertions, 10 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index ab6494818050..f5bbac6efb4c 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -54,8 +54,13 @@ static int sun4i_rgb_get_modes(struct drm_connector *connector)
 static int sun4i_rgb_mode_valid(struct drm_connector *connector,
                                 struct drm_display_mode *mode)
 {
+        struct sun4i_rgb *rgb = drm_connector_to_sun4i_rgb(connector);
+        struct sun4i_drv *drv = rgb->drv;
+        struct sun4i_tcon *tcon = drv->tcon;
         u32 hsync = mode->hsync_end - mode->hsync_start;
         u32 vsync = mode->vsync_end - mode->vsync_start;
+        unsigned long rate = mode->clock * 1000;
+        long rounded_rate;
 
         DRM_DEBUG_DRIVER("Validating modes...\n");
 
@@ -87,22 +92,21 @@ static int sun4i_rgb_mode_valid(struct drm_connector *connector,
 
         DRM_DEBUG_DRIVER("Vertical parameters OK\n");
 
-        return MODE_OK;
-}
+        rounded_rate = clk_round_rate(tcon->dclk, rate);
+        if (rounded_rate < rate)
+                return MODE_CLOCK_LOW;
 
-static struct drm_encoder *
-sun4i_rgb_best_encoder(struct drm_connector *connector)
-{
-        struct sun4i_rgb *rgb =
-                drm_connector_to_sun4i_rgb(connector);
+        if (rounded_rate > rate)
+                return MODE_CLOCK_HIGH;
 
-        return &rgb->encoder;
+        DRM_DEBUG_DRIVER("Clock rate OK\n");
+
+        return MODE_OK;
 }
 
 static struct drm_connector_helper_funcs sun4i_rgb_con_helper_funcs = {
         .get_modes      = sun4i_rgb_get_modes,
         .mode_valid     = sun4i_rgb_mode_valid,
-        .best_encoder   = sun4i_rgb_best_encoder,
 };
 
 static enum drm_connector_status
@@ -203,7 +207,7 @@ int sun4i_rgb_init(struct drm_device *drm)
         int ret;
 
         /* If we don't have a panel, there's no point in going on */
-        if (!tcon->panel)
+        if (IS_ERR(tcon->panel))
                 return -ENODEV;
 
         rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);