[Intel-gfx] [PATCH 13/14] drm/i915: Use intel_dp->DP in eDP PLL setup

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Use intel_dp->DP in the eDP PLL setup, instead of doing RMWs.

To do this we need to move DP_AUDIO_OUTPUT_ENABLE setup to happen later,
so that we don't enable audio accidentally while configuring the PLL.

Also intel_dp_link_down() must be made to update intel_dp->DP so that we
don't re-enable the port by accident when turning off the PLL. This is
safe now that we don't call intel_dp_link_down() during link retraining.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 41 ++++++++++++++---------------------------
 1 file changed, 14 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index e259803..63659e7 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1548,23 +1548,18 @@ static void ironlake_set_pll_cpu_edp(struct intel_dp *intel_dp)
 	struct intel_crtc *crtc = to_intel_crtc(dig_port->base.base.crtc);
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 dpa_ctl;
 
 	DRM_DEBUG_KMS("eDP PLL enable for clock %d\n",
 		      crtc->config->port_clock);
-	dpa_ctl = I915_READ(DP_A);
-	dpa_ctl &= ~DP_PLL_FREQ_MASK;
 
-	if (crtc->config->port_clock == 162000) {
-		dpa_ctl |= DP_PLL_FREQ_162MHZ;
+	intel_dp->DP &= ~DP_PLL_FREQ_MASK;
+
+	if (crtc->config->port_clock == 162000)
 		intel_dp->DP |= DP_PLL_FREQ_162MHZ;
-	} else {
-		dpa_ctl |= DP_PLL_FREQ_270MHZ;
+	else
 		intel_dp->DP |= DP_PLL_FREQ_270MHZ;
-	}
-
-	I915_WRITE(DP_A, dpa_ctl);
 
+	I915_WRITE(DP_A, intel_dp->DP);
 	POSTING_READ(DP_A);
 	udelay(500);
 }
@@ -1613,9 +1608,6 @@ static void intel_dp_prepare(struct intel_encoder *encoder)
 	intel_dp->DP |= DP_VOLTAGE_0_4 | DP_PRE_EMPHASIS_0;
 	intel_dp->DP |= DP_PORT_WIDTH(crtc->config->lane_count);
 
-	if (crtc->config->has_audio)
-		intel_dp->DP |= DP_AUDIO_OUTPUT_ENABLE;
-
 	/* Split out the IBX/CPU vs CPT settings */
 
 	if (IS_GEN7(dev) && port == PORT_A) {
@@ -2176,20 +2168,14 @@ static void ironlake_edp_pll_on(struct intel_dp *intel_dp)
 	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
 	struct intel_crtc *crtc = to_intel_crtc(intel_dig_port->base.base.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-	u32 dpa_ctl;
 
 	assert_pipe_disabled(dev_priv, crtc->pipe);
 	assert_dp_port_disabled(intel_dp);
 	assert_edp_pll_disabled(dev_priv);
 
 	DRM_DEBUG_KMS("\n");
-	dpa_ctl = I915_READ(DP_A);
-
-	/* We don't adjust intel_dp->DP while tearing down the link, to
-	 * facilitate link retraining (e.g. after hotplug). Hence clear all
-	 * enable bits here to ensure that we don't enable too much. */
-	intel_dp->DP &= ~(DP_PORT_EN | DP_AUDIO_OUTPUT_ENABLE);
 	intel_dp->DP |= DP_PLL_ENABLE;
+
 	I915_WRITE(DP_A, intel_dp->DP);
 	POSTING_READ(DP_A);
 	udelay(200);
@@ -2200,19 +2186,14 @@ static void ironlake_edp_pll_off(struct intel_dp *intel_dp)
 	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
 	struct intel_crtc *crtc = to_intel_crtc(intel_dig_port->base.base.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-	u32 dpa_ctl;
 
 	assert_pipe_disabled(dev_priv, crtc->pipe);
 	assert_dp_port_disabled(intel_dp);
 	assert_edp_pll_enabled(dev_priv);
 
-	dpa_ctl = I915_READ(DP_A);
+	intel_dp->DP &= ~DP_PLL_ENABLE;
 
-	/* We can't rely on the value tracked for the DP register in
-	 * intel_dp->DP because link_down must not change that (otherwise link
-	 * re-training will fail. */
-	dpa_ctl &= ~DP_PLL_ENABLE;
-	I915_WRITE(DP_A, dpa_ctl);
+	I915_WRITE(DP_A, intel_dp->DP);
 	POSTING_READ(DP_A);
 	udelay(200);
 }
@@ -2568,6 +2549,8 @@ static void intel_dp_enable_port(struct intel_dp *intel_dp)
 {
 	struct drm_device *dev = intel_dp_to_dev(intel_dp);
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *crtc =
+		to_intel_crtc(dp_to_dig_port(intel_dp)->base.base.crtc);
 
 	/* enable with pattern 1 (as per spec) */
 	_intel_dp_set_link_train(intel_dp, &intel_dp->DP,
@@ -2583,6 +2566,8 @@ static void intel_dp_enable_port(struct intel_dp *intel_dp)
 	 * fail when the power sequencer is freshly used for this port.
 	 */
 	intel_dp->DP |= DP_PORT_EN;
+	if (crtc->config->has_audio)
+		intel_dp->DP |= DP_AUDIO_OUTPUT_ENABLE;
 
 	I915_WRITE(intel_dp->output_reg, intel_dp->DP);
 	POSTING_READ(intel_dp->output_reg);
@@ -4028,6 +4013,8 @@ intel_dp_link_down(struct intel_dp *intel_dp)
 	}
 
 	msleep(intel_dp->panel_power_down_delay);
+
+	intel_dp->DP = DP;
 }
 
 static bool
-- 
2.4.10