drm/i915: make sure eDP PLL is enabled at the right time

We need to make sure the eDP PLL is enabled before the pipes or planes,
so do it as part of the DP prepare mode set function.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 58 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 8061a48804a3..caaaa8f9db3e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -831,6 +831,60 @@ static void ironlake_edp_backlight_off (struct drm_device *dev)
         I915_WRITE(PCH_PP_CONTROL, pp);
 }
 
+static void ironlake_edp_pll_on(struct drm_encoder *encoder)
+{
+        struct drm_device *dev = encoder->dev;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        u32 dpa_ctl;
+
+        DRM_DEBUG_KMS("\n");
+        dpa_ctl = I915_READ(DP_A);
+        dpa_ctl &= ~DP_PLL_ENABLE;
+        I915_WRITE(DP_A, dpa_ctl);
+}
+
+static void ironlake_edp_pll_off(struct drm_encoder *encoder)
+{
+        struct drm_device *dev = encoder->dev;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        u32 dpa_ctl;
+
+        dpa_ctl = I915_READ(DP_A);
+        dpa_ctl |= DP_PLL_ENABLE;
+        I915_WRITE(DP_A, dpa_ctl);
+        udelay(200);
+}
+
+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;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        uint32_t dp_reg = I915_READ(intel_dp->output_reg);
+
+        if (IS_eDP(intel_dp)) {
+                ironlake_edp_backlight_off(dev);
+                ironlake_edp_panel_on(dev);
+                ironlake_edp_pll_on(encoder);
+        }
+        if (dp_reg & DP_PORT_EN)
+                intel_dp_link_down(intel_dp);
+}
+
+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;
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        uint32_t dp_reg = I915_READ(intel_dp->output_reg);
+
+        if (!(dp_reg & DP_PORT_EN)) {
+                intel_dp_link_train(intel_dp);
+        }
+        if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
+                ironlake_edp_backlight_on(dev);
+}
+
 static void
 intel_dp_dpms(struct drm_encoder *encoder, int mode)
 {
@@ -846,6 +900,8 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode)
                 }
                 if (dp_reg & DP_PORT_EN)
                         intel_dp_link_down(intel_dp);
+                if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
+                        ironlake_edp_pll_off(encoder);
         } else {
                 if (!(dp_reg & DP_PORT_EN)) {
                         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
@@ -1427,9 +1483,9 @@ intel_dp_destroy (struct drm_connector *connector)
 static const struct drm_encoder_helper_funcs intel_dp_helper_funcs = {
         .dpms = intel_dp_dpms,
         .mode_fixup = intel_dp_mode_fixup,
-        .prepare = intel_encoder_prepare,
+        .prepare = intel_dp_prepare,
         .mode_set = intel_dp_mode_set,
-        .commit = intel_encoder_commit,
+        .commit = intel_dp_commit,
 };
 
 static const struct drm_connector_funcs intel_dp_connector_funcs = {