[Intel-gfx] [PATCH 3/6] drm/i915: reset eDP timestamps on resume

[Paulo Zanoni]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

The eDP code records a few timestamps containing the last time we took
some actions, because we need to wait before doing some other actions.
The problem is that if we store a timestamp when suspending and then
look at it when resuming, we'll ignore the unknown amount of time we
actually were suspended.

This happens with the panel power cycle delay: it's 500ms on my
machine, and it's delaying the resume sequence by 200ms due to a
timestamp we recorded before suspending. This patch should solve this
problem by resetting the timestamps, creating encoder->resume()
callbacks.

Q: Why don't we use DRM's connector->reset() callback?
A: Because it is also called then the driver is loaded, and it's on a point
where we have already used the panel, so we can't just reset any of the
timtestamps there.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c      |  2 ++
 drivers/gpu/drm/i915/intel_ddi.c     |  1 +
 drivers/gpu/drm/i915/intel_display.c | 11 +++++++++++
 drivers/gpu/drm/i915/intel_dp.c      | 21 +++++++++++++++++++++
 drivers/gpu/drm/i915/intel_drv.h     |  3 +++
 5 files changed, 38 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 61fb9fc..4aa42e5 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -649,6 +649,8 @@ static int __i915_drm_thaw(struct drm_device *dev, bool restore_gtt_mappings)
 
 		mutex_lock(&dev->struct_mutex);
 
+		intel_encoder_resume(dev);
+
 		error = i915_gem_init_hw(dev);
 		mutex_unlock(&dev->struct_mutex);
 
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 1488b28..527e89c 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1606,6 +1606,7 @@ void intel_ddi_init(struct drm_device *dev, enum port port)
 	intel_encoder->post_disable = intel_ddi_post_disable;
 	intel_encoder->get_hw_state = intel_ddi_get_hw_state;
 	intel_encoder->get_config = intel_ddi_get_config;
+	intel_encoder->resume = intel_dp_resume;
 
 	intel_dig_port->port = port;
 	intel_dig_port->saved_port_bits = I915_READ(DDI_BUF_CTL(port)) &
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 4d1357a..869be78 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11096,6 +11096,17 @@ void i915_redisable_vga(struct drm_device *dev)
 	}
 }
 
+void intel_encoder_resume(struct drm_device *dev)
+{
+	struct intel_encoder *encoder;
+
+	list_for_each_entry(encoder, &dev->mode_config.encoder_list,
+			    base.head) {
+		if (encoder->resume)
+			encoder->resume(encoder);
+	}
+}
+
 static void intel_modeset_readout_hw_state(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 2f82af4..a291977 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3393,6 +3393,26 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
 	}
 }
 
+void intel_dp_resume(struct intel_encoder *encoder)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
+	unsigned long tmp_jiffies = jiffies;
+
+	if (!is_edp(intel_dp))
+		return;
+
+	/*
+	 * Reset everything, otherwise when suspend/resume gets very fast, we
+	 * delay the resume based on the values that were set when we were still
+	 * suspending.
+	 */
+	intel_dp->last_power_on = tmp_jiffies - intel_dp->backlight_on_delay;
+	intel_dp->last_power_cycle = tmp_jiffies -
+				     intel_dp->panel_power_cycle_delay;
+	intel_dp->last_backlight_off = tmp_jiffies -
+				       intel_dp->backlight_off_delay;
+}
+
 static void
 intel_dp_init_panel_power_sequencer(struct drm_device *dev,
 				    struct intel_dp *intel_dp,
@@ -3784,6 +3804,7 @@ intel_dp_init(struct drm_device *dev, int output_reg, enum port port)
 	intel_encoder->post_disable = intel_post_disable_dp;
 	intel_encoder->get_hw_state = intel_dp_get_hw_state;
 	intel_encoder->get_config = intel_dp_get_config;
+	intel_encoder->resume = intel_dp_resume;
 	if (IS_VALLEYVIEW(dev)) {
 		intel_encoder->pre_pll_enable = vlv_dp_pre_pll_enable;
 		intel_encoder->pre_enable = vlv_pre_enable_dp;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 92de688..8fb6dbe 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -149,6 +149,7 @@ struct intel_encoder {
 	 * be set correctly before calling this function. */
 	void (*get_config)(struct intel_encoder *,
 			   struct intel_crtc_config *pipe_config);
+	void (*resume)(struct intel_encoder *);
 	int crtc_mask;
 	enum hpd_pin hpd_pin;
 };
@@ -711,6 +712,7 @@ void hsw_enable_ips(struct intel_crtc *crtc);
 void hsw_disable_ips(struct intel_crtc *crtc);
 void intel_display_set_init_power(struct drm_device *dev, bool enable);
 int valleyview_get_vco(struct drm_i915_private *dev_priv);
+void intel_encoder_resume(struct drm_device *dev);
 
 /* intel_dp.c */
 void intel_dp_init(struct drm_device *dev, int output_reg, enum port port);
@@ -734,6 +736,7 @@ void ironlake_edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync);
 void intel_edp_psr_enable(struct intel_dp *intel_dp);
 void intel_edp_psr_disable(struct intel_dp *intel_dp);
 void intel_edp_psr_update(struct drm_device *dev);
+void intel_dp_resume(struct intel_encoder *encoder);
 
 
 /* intel_dsi.c */
-- 
1.8.3.1