[Intel-gfx] [PATCH] drm/i915: edp resume/On time optimization.

[Kumar, Abhay]

Changed the implementation using boottime and removed jiffies. Please review and let us know if this is close.

-----Original Message-----
From: Kumar, Abhay 
Sent: Friday, December 18, 2015 11:55 AM
To: Intel-gfx at lists.freedesktop.org
Cc: Kumar, Abhay
Subject: [PATCH] drm/i915: edp resume/On time optimization.

From: Abhay Kumar <abhay.kumar at intel.com>

Make resume/on codepath not to wait for panel_power_cycle_delay(t11_t12) if this time is already spent in suspend/poweron time.

Change-Id: Ied0f10f82776af8e6e8ff561bb4e5c0ce1dad4b3
Signed-off-by: Abhay Kumar <abhay.kumar at intel.com>
---
 drivers/gpu/drm/i915/intel_ddi.c |  3 +++  drivers/gpu/drm/i915/intel_dp.c  | 22 ++++++++++++++--------  drivers/gpu/drm/i915/intel_drv.h |  2 +-
 3 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index cbabcb4..fe99d72 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2347,6 +2347,9 @@ static void intel_ddi_post_disable(struct intel_encoder *intel_encoder)
 		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF);
 		intel_edp_panel_vdd_on(intel_dp);
 		intel_edp_panel_off(intel_dp);
+
+		/* storing panel power off time */
+		intel_dp->panel_power_off_time = ktime_get_with_offset(TK_OFFS_BOOT);
 	}
 
 	if (IS_SKYLAKE(dev))
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index acda70e..845944d 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -38,7 +38,6 @@
 #include "intel_drv.h"
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
-
 #define DP_LINK_CHECK_TIMEOUT	(10 * 1000)
 
 /* Compliance test status bits  */
@@ -1654,13 +1653,22 @@ static void wait_panel_off(struct intel_dp *intel_dp)
 
 static void wait_panel_power_cycle(struct intel_dp *intel_dp)  {
+	ktime_t panel_power_on_time;
+	u32 panel_power_off_duration;
+
 	DRM_DEBUG_KMS("Wait for panel power cycle\n");
 
-	/* When we disable the VDD override bit last we have to do the manual
-	 * wait. */
-	wait_remaining_ms_from_jiffies(intel_dp->last_power_cycle,
-				       intel_dp->panel_power_cycle_delay);
+        /* take the diffrence of currrent time and panel power off time
+           and then make panel wait for t11_t12 if needed */
+	panel_power_on_time = ktime_get_with_offset(TK_OFFS_BOOT);
+	panel_power_off_duration = (panel_power_on_time.tv64 - intel_dp->panel_power_off_time.tv64);
+	panel_power_off_duration = panel_power_off_duration / 1000000;
 
+	/* When we disable the VDD override bit last we have to do the manual
+	 * wait */
+	if (panel_power_off_duration < intel_dp->panel_power_cycle_delay)
+		wait_remaining_ms_from_jiffies(jiffies,
+				       (intel_dp->panel_power_cycle_delay - 
+panel_power_off_duration));
 	wait_panel_status(intel_dp, IDLE_CYCLE_MASK, IDLE_CYCLE_VALUE);  }
 
@@ -1811,7 +1819,7 @@ static void edp_panel_vdd_off_sync(struct intel_dp *intel_dp)
 	I915_READ(pp_stat_reg), I915_READ(pp_ctrl_reg));
 
 	if ((pp & POWER_TARGET_ON) == 0)
-		intel_dp->last_power_cycle = jiffies;
+		intel_dp->panel_power_off_time = ktime_get_with_offset(TK_OFFS_BOOT);
 
 	power_domain = intel_display_port_power_domain(intel_encoder);
 	intel_display_power_put(dev_priv, power_domain); @@ -1960,7 +1968,6 @@ static void edp_panel_off(struct intel_dp *intel_dp)
 	I915_WRITE(pp_ctrl_reg, pp);
 	POSTING_READ(pp_ctrl_reg);
 
-	intel_dp->last_power_cycle = jiffies;
 	wait_panel_off(intel_dp);
 
 	/* We got a reference when we enabled the VDD. */ @@ -5196,7 +5203,6 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
 
 static void intel_dp_init_panel_power_timestamps(struct intel_dp *intel_dp)  {
-	intel_dp->last_power_cycle = jiffies;
 	intel_dp->last_power_on = jiffies;
 	intel_dp->last_backlight_off = jiffies;  } diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index d44f2f5..ef82e8f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -722,9 +722,9 @@ struct intel_dp {
 	int backlight_off_delay;
 	struct delayed_work panel_vdd_work;
 	bool want_panel_vdd;
-	unsigned long last_power_cycle;
 	unsigned long last_power_on;
 	unsigned long last_backlight_off;
+	ktime_t panel_power_off_time;
 
 	struct notifier_block edp_notifier;
 
--
1.9.1