drm/i915: Correct eDP panel power sequencing delay computations

Store the panel power sequencing delays in the dp private structure,
rather than the global device structure. Who knows, maybe we'll get
more than one eDP device in the future.

From the eDP spec, we need the following numbers:

 T1 + T3	Power on to Aux Channel operation (panel_power_up_delay)

		This marks how long it takes the panel to boot up and
		get ready to receive aux channel communications.

 T8		Video signal to backlight on (backlight_on_delay)

		Once a valid video signal is being sent to the device,
		it can take a while before the panel is actuall
		showing useful data. This delay allows the panel
		to get something reasonable up before the backlight
		is turned on.

 T9		Backlight off to video off (backlight_off_delay)

		Turning the backlight off can take a moment, so
		this delay makes sure there is still valid video
		data on the screen.

 T10		Video off to power off (panel_power_down_delay)

		Presumably this delay allows the panel to perform
		an orderly shutdown of the display.

 T11 + T12	Power off to power on (panel_power_cycle_delay)

		So, once you turn the panel off, you have to wait a
		while before you can turn it back on. This delay is
		usually the longest in the entire sequence.

Neither the VBIOS source code nor the hardware documentation has a
clear mapping between the delay values they provide and those required
by the eDP spec. The VBIOS code actually uses two different labels for
the delay values in the five words of the relevant VBT table.

**** MORE LATER ***

Look at both the current hardware register settings and the VBT
specified panel power sequencing timings. Use the maximum of the two
delays, to make sure things work reliably. If there is no VBT data,
then those values will be initialized to zero, so we'll just use the
values as programmed in the hardware. Note that the BIOS just fetches
delays from the VBT table to place in the hardware registers, so we
should get the same values from both places, except for rounding.

VBT doesn't provide any values for T1 or T2, so we'll always just use
the hardware value for that.

The panel power up delay is thus T1 + T2 + T3, which should be
sufficient in all cases.

The panel power down delay is T1 + T2 + T12, using T1+T2 as a proxy
for T11, which isn't available anywhere.

For the backlight delays, the eDP spec says T6 + T8 is the delay from the
end of link training to backlight on and T9 is the delay from
backlight off until video off. The hardware provides a 'backlight on'
delay, which I'm taking to be T6 + T8 while the VBT provides something
called 'T7', which I'm assuming is s

On the macbook air I'm testing with, this yields a power-up delay of
over 200ms and a power-down delay of over 600ms. It all works now, but
we're frobbing these power controls several times during mode setting,
making the whole process take an awfully long time.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 100 insertions, 35 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index a178414..ad682a5 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -59,6 +59,11 @@ struct intel_dp {
 	bool is_pch_edp;
 	uint8_t	train_set[4];
 	uint8_t link_status[DP_LINK_STATUS_SIZE];
+	int panel_power_up_delay;
+	int panel_power_down_delay;
+	int panel_power_cycle_delay;
+	int backlight_on_delay;
+	int backlight_off_delay;
 };
 
 /**
@@ -770,6 +775,9 @@ intel_dp_set_m_n(struct drm_crtc *crtc, struct drm_display_mode *mode,
 	}
 }
 
+static void ironlake_edp_pll_on(struct drm_encoder *encoder);
+static void ironlake_edp_pll_off(struct drm_encoder *encoder);
+
 static void
 intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
 		  struct drm_display_mode *adjusted_mode)
@@ -779,6 +787,14 @@ intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
 	struct drm_crtc *crtc = intel_dp->base.base.crtc;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 
+	/* Turn on the eDP PLL if needed */
+	if (is_edp(intel_dp)) {
+		if (!is_pch_edp(intel_dp))
+			ironlake_edp_pll_on(encoder);
+		else
+			ironlake_edp_pll_off(encoder);
+	}
+
 	intel_dp->DP = DP_VOLTAGE_0_4 | DP_PRE_EMPHASIS_0;
 	intel_dp->DP |= intel_dp->color_range;
 
@@ -838,16 +854,16 @@ static void ironlake_edp_panel_vdd_on(struct intel_dp *intel_dp)
 {
 	struct drm_device *dev = intel_dp->base.base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 pp;
+	u32 pp, pp_status;
 
 	if (!is_edp(intel_dp))
 		return;
+	DRM_DEBUG_KMS("Turn eDP VDD on\n");
 	/*
 	 * If the panel wasn't on, make sure there's not a currently
 	 * active PP sequence before enabling AUX VDD.
 	 */
-	if (!(I915_READ(PCH_PP_STATUS) & PP_ON))
-		msleep(dev_priv->panel_t3);
+	pp_status = I915_READ(PCH_PP_STATUS);
 
 	pp = I915_READ(PCH_PP_CONTROL);
 	pp &= ~PANEL_UNLOCK_MASK;
@@ -855,6 +871,12 @@ static void ironlake_edp_panel_vdd_on(struct intel_dp *intel_dp)
 	pp |= EDP_FORCE_VDD;
 	I915_WRITE(PCH_PP_CONTROL, pp);
 	POSTING_READ(PCH_PP_CONTROL);
+	DRM_DEBUG_KMS("PCH_PP_STATUS: 0x%08x PCH_PP_CONTROL: 0x%08x\n",
+		      I915_READ(PCH_PP_STATUS), I915_READ(PCH_PP_CONTROL));
+	if (!(pp_status & PP_ON)) {
+		msleep(intel_dp->panel_power_up_delay);
+		DRM_DEBUG_KMS("eDP VDD was not on\n");
+	}
 }
 
 static void ironlake_edp_panel_vdd_off(struct intel_dp *intel_dp)
@@ -865,6 +887,7 @@ static void ironlake_edp_panel_vdd_off(struct intel_dp *intel_dp)
 
 	if (!is_edp(intel_dp))
 		return;
+	DRM_DEBUG_KMS("Turn eDP VDD off\n");
 	pp = I915_READ(PCH_PP_CONTROL);
 	pp &= ~PANEL_UNLOCK_MASK;
 	pp |= PANEL_UNLOCK_REGS;
@@ -873,7 +896,9 @@ static void ironlake_edp_panel_vdd_off(struct intel_dp *intel_dp)
 	POSTING_READ(PCH_PP_CONTROL);
 
 	/* Make sure sequencer is idle before allowing subsequent activity */
-	msleep(dev_priv->panel_t12);
+	DRM_DEBUG_KMS("PCH_PP_STATUS: 0x%08x PCH_PP_CONTROL: 0x%08x\n",
+		      I915_READ(PCH_PP_STATUS), I915_READ(PCH_PP_CONTROL));
+	msleep(intel_dp->panel_power_cycle_delay);
 }
 
 /* Returns true if the panel was already on when called */
@@ -884,7 +909,7 @@ static bool ironlake_edp_panel_on (struct intel_dp *intel_dp)
 	u32 pp, idle_on_mask = PP_ON | PP_SEQUENCE_STATE_ON_IDLE;
 
 	if (!is_edp(intel_dp))
-		return;
+		return true;
 	if (I915_READ(PCH_PP_STATUS) & PP_ON)
 		return true;
 
@@ -913,8 +938,10 @@ static bool ironlake_edp_panel_on (struct intel_dp *intel_dp)
 	return false;
 }
 
-static void ironlake_edp_panel_off (struct drm_device *dev)
+static void ironlake_edp_panel_off(struct drm_encoder *encoder)
 {
+	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+	struct drm_device *dev = encoder->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	u32 pp, idle_off_mask = PP_ON | PP_SEQUENCE_MASK |
 		PP_CYCLE_DELAY_ACTIVE | PP_SEQUENCE_STATE_MASK;
@@ -933,6 +960,7 @@ static void ironlake_edp_panel_off (struct drm_device *dev)
 	pp &= ~POWER_TARGET_ON;
 	I915_WRITE(PCH_PP_CONTROL, pp);
 	POSTING_READ(PCH_PP_CONTROL);
+	msleep(intel_dp->panel_power_cycle_delay);
 
 	if (wait_for((I915_READ(PCH_PP_STATUS) & idle_off_mask) == 0, 5000))
 		DRM_ERROR("panel off wait timed out: 0x%08x\n",
@@ -943,11 +971,15 @@ static void ironlake_edp_panel_off (struct drm_device *dev)
 	POSTING_READ(PCH_PP_CONTROL);
 }
 
-static void ironlake_edp_backlight_on (struct drm_device *dev)
+static void ironlake_edp_backlight_on (struct intel_dp *intel_dp)
 {
+	struct drm_device *dev = intel_dp->base.base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	u32 pp;
 
+	if (!is_edp(intel_dp))
+		return;
+
 	DRM_DEBUG_KMS("\n");
 	/*
 	 * If we enable the backlight right away following a panel power
@@ -955,25 +987,32 @@ static void ironlake_edp_backlight_on (struct drm_device *dev)
 	 * link.  So delay a bit to make sure the image is solid before
 	 * allowing it to appear.
 	 */
-	msleep(300);
+	msleep(intel_dp->backlight_on_delay);
 	pp = I915_READ(PCH_PP_CONTROL);
 	pp &= ~PANEL_UNLOCK_MASK;
 	pp |= PANEL_UNLOCK_REGS;
 	pp |= EDP_BLC_ENABLE;
 	I915_WRITE(PCH_PP_CONTROL, pp);
+	POSTING_READ(PCH_PP_CONTROL);
 }
 
-static void ironlake_edp_backlight_off (struct drm_device *dev)
+static void ironlake_edp_backlight_off (struct intel_dp *intel_dp)
 {
+	struct drm_device *dev = intel_dp->base.base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	u32 pp;
 
+	if (!is_edp(intel_dp))
+		return;
+
 	DRM_DEBUG_KMS("\n");
 	pp = I915_READ(PCH_PP_CONTROL);
 	pp &= ~PANEL_UNLOCK_MASK;
 	pp |= PANEL_UNLOCK_REGS;
 	pp &= ~EDP_BLC_ENABLE;
 	I915_WRITE(PCH_PP_CONTROL, pp);
+	POSTING_READ(PCH_PP_CONTROL);
+	msleep(intel_dp->backlight_off_delay);
 }
 
 static void ironlake_edp_pll_on(struct drm_encoder *encoder)
@@ -1036,40 +1075,31 @@ static void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode)
 static void intel_dp_prepare(struct drm_encoder *encoder)
 {
 	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
-	struct drm_device *dev = encoder->dev;
 
 	/* Wake up the sink first */
 	ironlake_edp_panel_vdd_on(intel_dp);
 	intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
 	ironlake_edp_panel_vdd_off(intel_dp);
 
-	if (is_edp(intel_dp)) {
-		ironlake_edp_backlight_off(dev);
-		ironlake_edp_panel_off(dev);
-		if (!is_pch_edp(intel_dp))
-			ironlake_edp_pll_on(encoder);
-		else
-			ironlake_edp_pll_off(encoder);
-	}
+	/* Make sure the panel is off before trying to
+	 * change the mode
+	 */
+	ironlake_edp_backlight_off(intel_dp);
 	intel_dp_link_down(intel_dp);
+	ironlake_edp_panel_off(encoder);
 }
 
 static void intel_dp_commit(struct drm_encoder *encoder)
 {
 	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
-	struct drm_device *dev = encoder->dev;
 
 	ironlake_edp_panel_vdd_on(intel_dp);
-
+	intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
 	intel_dp_start_link_train(intel_dp);
-
 	ironlake_edp_panel_on(intel_dp);
 	ironlake_edp_panel_vdd_off(intel_dp);
-
 	intel_dp_complete_link_train(intel_dp);
-
-	if (is_edp(intel_dp))
-		ironlake_edp_backlight_on(dev);
+	ironlake_edp_backlight_on(intel_dp);
 
 	intel_dp->dpms_mode = DRM_MODE_DPMS_ON;
 }
@@ -1085,10 +1115,10 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode)
 	if (mode != DRM_MODE_DPMS_ON) {
 		ironlake_edp_panel_vdd_on(intel_dp);
 		if (is_edp(intel_dp))
-			ironlake_edp_backlight_off(dev);
+			ironlake_edp_backlight_off(intel_dp);
 		intel_dp_sink_dpms(intel_dp, mode);
 		intel_dp_link_down(intel_dp);
-		ironlake_edp_panel_off(dev);
+		ironlake_edp_panel_off(encoder);
 		if (is_edp(intel_dp) && !is_pch_edp(intel_dp))
 			ironlake_edp_pll_off(encoder);
 		ironlake_edp_panel_vdd_off(intel_dp);
@@ -1100,10 +1130,9 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode)
 			ironlake_edp_panel_on(intel_dp);
 			ironlake_edp_panel_vdd_off(intel_dp);
 			intel_dp_complete_link_train(intel_dp);
+			ironlake_edp_backlight_on(intel_dp);
 		} else
 			ironlake_edp_panel_vdd_off(intel_dp);
-		if (is_edp(intel_dp))
-			ironlake_edp_backlight_on(dev);
 	}
 	intel_dp->dpms_mode = mode;
 }
@@ -1626,6 +1655,7 @@ intel_dp_link_down(struct intel_dp *intel_dp)
 
 	I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN);
 	POSTING_READ(intel_dp->output_reg);
+	msleep(intel_dp->panel_power_down_delay);
 }
 
 static bool
@@ -2117,16 +2147,51 @@ intel_dp_init(struct drm_device *dev, int output_reg)
 	/* Cache some DPCD data in the eDP case */
 	if (is_edp(intel_dp)) {
 		bool ret;
-		u32 pp_on, pp_div;
+		struct edp_power_seq	cur, vbt;
+		u32 pp_on, pp_off, pp_div;
 
 		pp_on = I915_READ(PCH_PP_ON_DELAYS);
+		pp_off = I915_READ(PCH_PP_OFF_DELAYS);
 		pp_div = I915_READ(PCH_PP_DIVISOR);
 
-		/* Get T3 & T12 values (note: VESA not bspec terminology) */
-		dev_priv->panel_t3 = (pp_on & 0x1fff0000) >> 16;
-		dev_priv->panel_t3 /= 10; /* t3 in 100us units */
-		dev_priv->panel_t12 = pp_div & 0xf;
-		dev_priv->panel_t12 *= 100; /* t12 in 100ms units */
+		/* Pull timing values out of registers */
+		cur.t1_t3 = (pp_on & PANEL_POWER_UP_DELAY_MASK) >>
+			PANEL_POWER_UP_DELAY_SHIFT;
+
+		cur.t8 = (pp_on & PANEL_LIGHT_ON_DELAY_MASK) >>
+			PANEL_LIGHT_ON_DELAY_SHIFT;
+		
+		cur.t9 = (pp_off & PANEL_LIGHT_OFF_DELAY_MASK) >>
+			PANEL_LIGHT_OFF_DELAY_SHIFT;
+
+		cur.t10 = (pp_off & PANEL_POWER_DOWN_DELAY_MASK) >>
+			PANEL_POWER_DOWN_DELAY_SHIFT;
+
+		cur.t11_t12 = ((pp_div & PANEL_POWER_CYCLE_DELAY_MASK) >>
+			       PANEL_POWER_CYCLE_DELAY_SHIFT) * 1000;
+
+		DRM_DEBUG_KMS("cur t1_t3 %d t8 %d t9 %d t10 %d t11_t12 %d\n",
+			      cur.t1_t3, cur.t8, cur.t9, cur.t10, cur.t11_t12);
+
+		vbt = dev_priv->edp.pps;
+
+		DRM_DEBUG_KMS("vbt t1_t3 %d t8 %d t9 %d t10 %d t11_t12 %d\n",
+			      vbt.t1_t3, vbt.t8, vbt.t9, vbt.t10, vbt.t11_t12);
+
+#define get_delay(field)	((max(cur.field, vbt.field) + 9) / 10)
+
+		intel_dp->panel_power_up_delay = get_delay(t1_t3);
+		intel_dp->backlight_on_delay = get_delay(t8);
+		intel_dp->backlight_off_delay = get_delay(t9);
+		intel_dp->panel_power_down_delay = get_delay(t10);
+		intel_dp->panel_power_cycle_delay = get_delay(t11_t12);
+
+		DRM_DEBUG_KMS("panel power up delay %d, power down delay %d, power cycle delay %d\n",
+			      intel_dp->panel_power_up_delay, intel_dp->panel_power_down_delay,
+			      intel_dp->panel_power_cycle_delay);
+
+		DRM_DEBUG_KMS("backlight on delay %d, off delay %d\n",
+			      intel_dp->backlight_on_delay, intel_dp->backlight_off_delay);
 
 		ironlake_edp_panel_vdd_on(intel_dp);
 		ret = intel_dp_get_dpcd(intel_dp);