[PATCH 1/2] drm/i915: remove now unnecessary delays in eDP panel power sequencing

[PATCH 1/2] drm/i915: remove now unnecessary delays in eDP panel power sequencing

[Jesse Barnes]

Now that we're doing the right thing elsewhere, these are no longer
necessary.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_dp.c |   10 ----------
 1 files changed, 0 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index c768e30..3d07a73 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -834,11 +834,6 @@ static bool ironlake_edp_panel_on (struct intel_dp *intel_dp)
 	I915_WRITE(PCH_PP_CONTROL, pp);
 	POSTING_READ(PCH_PP_CONTROL);
 
-	/* Ouch. We need to wait here for some panels, like Dell e6510
-	 * https://bugs.freedesktop.org/show_bug.cgi?id=29278i
-	 */
-	msleep(300);
-
 	if (wait_for((I915_READ(PCH_PP_STATUS) & idle_on_mask) == idle_on_mask,
 		     5000))
 		DRM_ERROR("panel on wait timed out: 0x%08x\n",
@@ -875,11 +870,6 @@ static void ironlake_edp_panel_off (struct drm_device *dev)
 	pp |= PANEL_POWER_RESET; /* restore panel reset bit */
 	I915_WRITE(PCH_PP_CONTROL, pp);
 	POSTING_READ(PCH_PP_CONTROL);
-
-	/* Ouch. We need to wait here for some panels, like Dell e6510
-	 * https://bugs.freedesktop.org/show_bug.cgi?id=29278i
-	 */
-	msleep(300);
 }
 
 static void ironlake_edp_backlight_on (struct drm_device *dev)
-- 
1.7.1

[PATCH 2/2] drm/i915: use VDD AUX override to make panel power sequencing look better

[Jesse Barnes]

Rather than power cycling the panel when there are no bits to display,
use the VDD AUX bit to power the panel up just enough for DP AUX
transactions to work.  This prevents a bit of unnecessary ugliness as
mode sets occur on the panel.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_drv.h |    1 +
 drivers/gpu/drm/i915/intel_dp.c |   65 ++++++++++++++++++++++++++++++++++----
 2 files changed, 59 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0e167e4..fc23fae 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -647,6 +647,7 @@ typedef struct drm_i915_private {
 	unsigned int lvds_border_bits;
 	/* Panel fitter placement and size for Ironlake+ */
 	u32 pch_pf_pos, pch_pf_size;
+	int panel_t3, panel_t12;
 
 	struct drm_crtc *plane_to_crtc_mapping[2];
 	struct drm_crtc *pipe_to_crtc_mapping[2];
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 3d07a73..a0d019a 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -813,6 +813,40 @@ intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
 	}
 }
 
+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;
+
+	/*
+	 * 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 = I915_READ(PCH_PP_CONTROL);
+	pp |= EDP_FORCE_VDD;
+	I915_WRITE(PCH_PP_CONTROL, pp);
+	POSTING_READ(PCH_PP_CONTROL);
+}
+
+static void ironlake_edp_panel_vdd_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;
+
+	pp = I915_READ(PCH_PP_CONTROL);
+	pp &= ~EDP_FORCE_VDD;
+	I915_WRITE(PCH_PP_CONTROL, pp);
+	POSTING_READ(PCH_PP_CONTROL);
+
+	/* Make sure sequencer is idle before allowing subsequent activity */
+	msleep(dev_priv->panel_t12);
+}
+
 /* Returns true if the panel was already on when called */
 static bool ironlake_edp_panel_on (struct intel_dp *intel_dp)
 {
@@ -935,7 +969,7 @@ static void intel_dp_prepare(struct drm_encoder *encoder)
 
 	if (is_edp(intel_dp)) {
 		ironlake_edp_backlight_off(dev);
-		ironlake_edp_panel_on(intel_dp);
+		ironlake_edp_panel_off(dev);
 		if (!is_pch_edp(intel_dp))
 			ironlake_edp_pll_on(encoder);
 		else
@@ -949,10 +983,15 @@ 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;
 
+	if (is_edp(intel_dp))
+		ironlake_edp_panel_vdd_on(intel_dp);
+
 	intel_dp_start_link_train(intel_dp);
 
-	if (is_edp(intel_dp))
+	if (is_edp(intel_dp)) {
 		ironlake_edp_panel_on(intel_dp);
+		ironlake_edp_panel_vdd_off(intel_dp);
+	}
 
 	intel_dp_complete_link_train(intel_dp);
 
@@ -978,9 +1017,13 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode)
 			ironlake_edp_pll_off(encoder);
 	} else {
 		if (is_edp(intel_dp))
-			ironlake_edp_panel_on(intel_dp);
+			ironlake_edp_panel_vdd_on(intel_dp);
 		if (!(dp_reg & DP_PORT_EN)) {
 			intel_dp_start_link_train(intel_dp);
+			if (is_edp(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))
@@ -1863,9 +1906,18 @@ intel_dp_init(struct drm_device *dev, int output_reg)
 	/* Cache some DPCD data in the eDP case */
 	if (is_edp(intel_dp)) {
 		int ret;
-		bool was_on;
+		u32 pp_on, pp_div;
+
+		pp_on = I915_READ(PCH_PP_ON_DELAYS);
+		pp_div = I915_READ(PCH_PP_DIVISOR);
 
-		was_on = ironlake_edp_panel_on(intel_dp);
+		/* 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 */
+
+		ironlake_edp_panel_vdd_on(intel_dp);
 		ret = intel_dp_aux_native_read(intel_dp, DP_DPCD_REV,
 					       intel_dp->dpcd,
 					       sizeof(intel_dp->dpcd));
@@ -1876,8 +1928,7 @@ intel_dp_init(struct drm_device *dev, int output_reg)
 		} else {
 			DRM_ERROR("failed to retrieve link info\n");
 		}
-		if (!was_on)
-			ironlake_edp_panel_off(dev);
+		ironlake_edp_panel_vdd_off(intel_dp);
 	}
 
 	intel_encoder->hot_plug = intel_dp_hot_plug;
-- 
1.7.1

Re: [PATCH 2/2] drm/i915: use VDD AUX override to make panel power sequencing look better

[Chris Wilson]

On Mon, 24 Jan 2011 17:10:54 -0800, Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> Rather than power cycling the panel when there are no bits to display,
> use the VDD AUX bit to power the panel up just enough for DP AUX
> transactions to work.  This prevents a bit of unnecessary ugliness as
> mode sets occur on the panel.

Applied both to -next, thanks.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre