drm/i915: only set TV mode when any property changed

If there's no real property change, don't need to set TV mode again.

Signed-off-by: Zhenyu Wang <zhenyu.z.wang@intel.com>
[anholt: checkpatch.pl fix]
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 20 insertions, 7 deletions

diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
index ceca9471a75a..5d9ca779ce25 100644
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -1571,32 +1571,45 @@ intel_tv_set_property(struct drm_connector *connector, struct drm_property *prop
         struct intel_output *intel_output = to_intel_output(connector);
         struct intel_tv_priv *tv_priv = intel_output->dev_priv;
         int ret = 0;
+        bool changed = false;
 
         ret = drm_connector_property_set_value(connector, property, val);
         if (ret < 0)
                 goto out;
 
-        if (property == dev->mode_config.tv_left_margin_property)
+        if (property == dev->mode_config.tv_left_margin_property &&
+                tv_priv->margin[TV_MARGIN_LEFT] != val) {
                 tv_priv->margin[TV_MARGIN_LEFT] = val;
-        else if (property == dev->mode_config.tv_right_margin_property)
+                changed = true;
+        } else if (property == dev->mode_config.tv_right_margin_property &&
+                tv_priv->margin[TV_MARGIN_RIGHT] != val) {
                 tv_priv->margin[TV_MARGIN_RIGHT] = val;
-        else if (property == dev->mode_config.tv_top_margin_property)
+                changed = true;
+        } else if (property == dev->mode_config.tv_top_margin_property &&
+                tv_priv->margin[TV_MARGIN_TOP] != val) {
                 tv_priv->margin[TV_MARGIN_TOP] = val;
-        else if (property == dev->mode_config.tv_bottom_margin_property)
+                changed = true;
+        } else if (property == dev->mode_config.tv_bottom_margin_property &&
+                tv_priv->margin[TV_MARGIN_BOTTOM] != val) {
                 tv_priv->margin[TV_MARGIN_BOTTOM] = val;
-        else if (property == dev->mode_config.tv_mode_property) {
+                changed = true;
+        } else if (property == dev->mode_config.tv_mode_property) {
                 if (val >= NUM_TV_MODES) {
                         ret = -EINVAL;
                         goto out;
                 }
+                if (!strcmp(tv_priv->tv_format, tv_modes[val].name))
+                        goto out;
+
                 tv_priv->tv_format = tv_modes[val].name;
-                intel_tv_mode_set(&intel_output->enc, NULL, NULL);
+                changed = true;
         } else {
                 ret = -EINVAL;
                 goto out;
         }
 
-        intel_tv_mode_set(&intel_output->enc, NULL, NULL);
+        if (changed)
+                intel_tv_mode_set(&intel_output->enc, NULL, NULL);
 out:
         return ret;
 }