[Intel-gfx] [PATCH 3/4] drm/i915: make sure VDD is turned off during system suspend

[Imre Deak]

Atm we may leave eDP VDD enabled during system suspend after the CRTCs
are disabled through an HPD->DPCD read event. So disable VDD during
suspend at a point when no HPDs can occur.

Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c  | 15 +++++++++++++++
 drivers/gpu/drm/i915/intel_dp.c  | 13 +++++++++++--
 drivers/gpu/drm/i915/intel_drv.h |  6 ++++++
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 0653761..1c7979e 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -501,6 +501,19 @@ void intel_hpd_cancel_work(struct drm_i915_private *dev_priv)
 	cancel_delayed_work_sync(&dev_priv->hotplug_reenable_work);
 }
 
+static void intel_suspend_encoders(struct drm_i915_private *dev_priv)
+{
+	struct drm_device *dev = dev_priv->dev;
+	struct intel_encoder *intel_encoder;
+
+	drm_modeset_lock_all(dev);
+	for_each_intel_encoder(dev, intel_encoder) {
+		if (intel_encoder->suspend)
+			intel_encoder->suspend(intel_encoder);
+	}
+	drm_modeset_unlock_all(dev);
+}
+
 static int i915_drm_freeze(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -547,6 +560,8 @@ static int i915_drm_freeze(struct drm_device *dev)
 		intel_runtime_pm_disable_interrupts(dev);
 		intel_hpd_cancel_work(dev_priv);
 
+		intel_suspend_encoders(dev_priv);
+
 		intel_suspend_gt_powersave(dev);
 
 		intel_modeset_suspend_hw(dev);
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 34e3c47..d7f5d0a 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1291,8 +1291,6 @@ static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
 	if (!is_edp(intel_dp))
 		return;
 
-	WARN(!intel_dp->want_panel_vdd, "eDP VDD not forced on");
-
 	intel_dp->want_panel_vdd = false;
 
 	if (sync)
@@ -4003,6 +4001,16 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
 	kfree(intel_dig_port);
 }
 
+void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(&intel_encoder->base);
+
+	if (!is_edp(intel_dp))
+		return;
+
+	edp_panel_vdd_off(intel_dp, true);
+}
+
 static void intel_dp_encoder_reset(struct drm_encoder *encoder)
 {
 	intel_edp_panel_vdd_sanitize(to_intel_encoder(encoder));
@@ -4722,6 +4730,7 @@ intel_dp_init(struct drm_device *dev, int output_reg, enum port port)
 	intel_encoder->disable = intel_disable_dp;
 	intel_encoder->get_hw_state = intel_dp_get_hw_state;
 	intel_encoder->get_config = intel_dp_get_config;
+	intel_encoder->suspend = intel_dp_encoder_suspend;
 	if (IS_CHERRYVIEW(dev)) {
 		intel_encoder->pre_pll_enable = chv_dp_pre_pll_enable;
 		intel_encoder->pre_enable = chv_pre_enable_dp;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 1b3d1d7..cefd337 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -153,6 +153,12 @@ struct intel_encoder {
 	 * be set correctly before calling this function. */
 	void (*get_config)(struct intel_encoder *,
 			   struct intel_crtc_config *pipe_config);
+	/*
+	 * Called during system suspend after all pending requests for the
+	 * encoder are flushed (for example for DP AUX transactions) and
+	 * device interrupts are disabled.
+	 */
+	void (*suspend)(struct intel_encoder *);
 	int crtc_mask;
 	enum hpd_pin hpd_pin;
 };
-- 
1.8.4