[Intel-gfx] [PATCH 01/11] CHROMIUM: drm/i915: add backlight assertion funcs for PWM status

[clinton.a.taylor at intel.com]

From: Jesse Barnes <jbarnes at virtuousgeek.org>

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
Signed-off-by: Wayne Boyer <wayne.boyer at intel.com>

Change-Id: I0838b7c84f1913e1026ad98b8b2e79eb133d17e3
Reviewed-on: https://chromium-review.googlesource.com/192468
Reviewed-by: Stéphane Marchesin <marcheu at chromium.org>
Reviewed-by: Aaron Durbin <adurbin at chromium.org>
Tested-by: Wayne Boyer <wayne.boyer at intel.com>
Commit-Queue: Wayne Boyer <wayne.boyer at intel.com>

Conflicts:
	drivers/gpu/drm/i915/intel_dp.c
---
 drivers/gpu/drm/i915/intel_dp.c |   22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 2adb727..90b24f6 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -369,6 +369,21 @@ static int edp_notify_handler(struct notifier_block *this, unsigned long code,
 	return 0;
 }
 
+static void assert_pwm(struct drm_i915_private *dev_priv,
+		       struct intel_connector *connector,
+		       bool expected_state)
+{
+	bool state;
+
+	state = dev_priv->display.get_backlight(connector);
+
+	WARN(state != expected_state, "pwm state failure, expected %d, found "
+	     "%d\n", expected_state, state);
+}
+
+#define assert_pwm_enabled(d, p) assert_pwm((d), (p), true)
+#define assert_pwm_disabled(d, p) assert_pwm((d), (p), false)
+
 static bool edp_have_panel_power(struct intel_dp *intel_dp)
 {
 	struct drm_device *dev = intel_dp_to_dev(intel_dp);
@@ -1351,6 +1366,8 @@ void intel_edp_panel_off(struct intel_dp *intel_dp)
 
 	WARN(!intel_dp->want_panel_vdd, "Need VDD to turn off panel\n");
 
+	assert_pwm_disabled(dev_priv, intel_dp->attached_connector);
+
 	pp = ironlake_get_pp_control(intel_dp);
 	/* We need to switch off panel power _and_ force vdd, for otherwise some
 	 * panels get very unhappy and cease to work. */
@@ -1387,6 +1404,8 @@ void intel_edp_backlight_on(struct intel_dp *intel_dp)
 
 	intel_panel_enable_backlight(intel_dp->attached_connector);
 
+	assert_pwm_disabled(dev_priv, intel_dp->attached_connector);
+
 	/*
 	 * If we enable the backlight right away following a panel power
 	 * on, we may see slight flicker as the panel syncs with the eDP
@@ -1415,6 +1434,9 @@ void intel_edp_backlight_off(struct intel_dp *intel_dp)
 
 	DRM_DEBUG_KMS("\n");
 	pp = ironlake_get_pp_control(intel_dp);
+
+	assert_pwm_enabled(dev_priv, intel_dp->attached_connector);
+
 	pp &= ~EDP_BLC_ENABLE;
 
 	pp_ctrl_reg = _pp_ctrl_reg(intel_dp);
-- 
1.7.9.5