[PATCH 15/14] drm/i915: Add comments explaining the vdd on/off functions

ville.syrjala
2014-08-19T17:50:02Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Jani wanted some comments to explain why we call certain vdd on/off
functions in certain places.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/intel_dp.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 1067082..1233a10 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1315,6 +1315,7 @@ static u32 ironlake_get_pp_control(struct intel_dp *intel_dp)
return control;
}

+/* should be paired with edp_panel_vdd_off() */
static bool edp_panel_vdd_on(struct intel_dp *intel_dp)
{
struct drm_device *dev = intel_dp_to_dev(intel_dp);
@@ -1365,6 +1366,7 @@ static bool edp_panel_vdd_on(struct intel_dp *intel_dp)
return need_to_disable;
}

+/* should be paired with intel_edp_panel_vdd_off() */
void intel_edp_panel_vdd_on(struct intel_dp *intel_dp)
{
struct drm_i915_private *dev_priv =
@@ -1447,6 +1449,7 @@ static void edp_panel_vdd_schedule_off(struct intel_dp *intel_dp)
schedule_delayed_work(&intel_dp->panel_vdd_work, delay);
}

+/* should be paired with edp_panel_vdd_on() */
static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
{
struct drm_i915_private *dev_priv =
@@ -1467,6 +1470,7 @@ static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
edp_panel_vdd_schedule_off(intel_dp);
}

+/* should be paired with intel_edp_panel_vdd_on() */
static void intel_edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
{
struct drm_i915_private *dev_priv =
@@ -4307,6 +4311,10 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
drm_encoder_cleanup(encoder);
if (is_edp(intel_dp)) {
cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
+ /*
+ * vdd might still be enabled do to the delayed vdd off.
+ * Make sure vdd is actually turned off here.
+ */
mutex_lock(&dev_priv->pps_mutex);
edp_panel_vdd_off_sync(intel_dp);
mutex_unlock(&dev_priv->pps_mutex);
@@ -4327,6 +4335,10 @@ static void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder)
if (!is_edp(intel_dp))
return;

+ /*
+ * vdd might still be enabled do to the delayed vdd off.
+ * Make sure vdd is actually turned off here.
+ */
mutex_lock(&dev_priv->pps_mutex);
edp_panel_vdd_off_sync(intel_dp);
mutex_unlock(&dev_priv->pps_mutex);
@@ -5025,6 +5037,10 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
drm_dp_aux_unregister(&intel_dp->aux);
if (is_edp(intel_dp)) {
cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
+ /*
+ * vdd might still be enabled do to the delayed vdd off.
+ * Make sure vdd is actually turned off here.
+ */
mutex_lock(&dev_priv->pps_mutex);
edp_panel_vdd_off_sync(intel_dp);
mutex_unlock(&dev_priv->pps_mutex);
--
1.8.5.5