drm/i915/gen9+: Enable hotplug detection early

For LSPCON resume time initialization we need to sample the
corresponding pin's HPD level, but this is only available when HPD
detection is enabled. Currently we enable detection only when enabling
HPD interrupts which is too late, so bring the enabling of detection
earlier.

This is needed by the next patch.

Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1485509961-9010-2-git-send-email-imre.deak@intel.com
(cherry picked from commit 7fff8126d9cc902b2636d05d5d34894a75174993)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/i915_irq.c

@@ -3123,19 +3123,16 @@ static void ibx_hpd_irq_setup(struct drm_i915_private *dev_priv)
 	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
 }
 
-static void spt_hpd_irq_setup(struct drm_i915_private *dev_priv)
+static void spt_hpd_detection_setup(struct drm_i915_private *dev_priv)
 {
-	u32 hotplug_irqs, hotplug, enabled_irqs;
-
-	hotplug_irqs = SDE_HOTPLUG_MASK_SPT;
-	enabled_irqs = intel_hpd_enabled_irqs(dev_priv, hpd_spt);
-
-	ibx_display_interrupt_update(dev_priv, hotplug_irqs, enabled_irqs);
+	u32 hotplug;
 
 	/* Enable digital hotplug on the PCH */
 	hotplug = I915_READ(PCH_PORT_HOTPLUG);
-	hotplug |= PORTD_HOTPLUG_ENABLE | PORTC_HOTPLUG_ENABLE |
-		PORTB_HOTPLUG_ENABLE | PORTA_HOTPLUG_ENABLE;
+	hotplug |= PORTA_HOTPLUG_ENABLE |
+		   PORTB_HOTPLUG_ENABLE |
+		   PORTC_HOTPLUG_ENABLE |
+		   PORTD_HOTPLUG_ENABLE;
 	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
 
 	hotplug = I915_READ(PCH_PORT_HOTPLUG2);
@@ -3143,6 +3140,18 @@ static void spt_hpd_irq_setup(struct drm_i915_private *dev_priv)
 	I915_WRITE(PCH_PORT_HOTPLUG2, hotplug);
 }
 
+static void spt_hpd_irq_setup(struct drm_i915_private *dev_priv)
+{
+	u32 hotplug_irqs, enabled_irqs;
+
+	hotplug_irqs = SDE_HOTPLUG_MASK_SPT;
+	enabled_irqs = intel_hpd_enabled_irqs(dev_priv, hpd_spt);
+
+	ibx_display_interrupt_update(dev_priv, hotplug_irqs, enabled_irqs);
+
+	spt_hpd_detection_setup(dev_priv);
+}
+
 static void ilk_hpd_irq_setup(struct drm_i915_private *dev_priv)
 {
 	u32 hotplug_irqs, hotplug, enabled_irqs;
@@ -3177,18 +3186,15 @@ static void ilk_hpd_irq_setup(struct drm_i915_private *dev_priv)
 	ibx_hpd_irq_setup(dev_priv);
 }
 
-static void bxt_hpd_irq_setup(struct drm_i915_private *dev_priv)
+static void __bxt_hpd_detection_setup(struct drm_i915_private *dev_priv,
+				      u32 enabled_irqs)
 {
-	u32 hotplug_irqs, hotplug, enabled_irqs;
-
-	enabled_irqs = intel_hpd_enabled_irqs(dev_priv, hpd_bxt);
-	hotplug_irqs = BXT_DE_PORT_HOTPLUG_MASK;
-
-	bdw_update_port_irq(dev_priv, hotplug_irqs, enabled_irqs);
+	u32 hotplug;
 
 	hotplug = I915_READ(PCH_PORT_HOTPLUG);
-	hotplug |= PORTC_HOTPLUG_ENABLE | PORTB_HOTPLUG_ENABLE |
-		PORTA_HOTPLUG_ENABLE;
+	hotplug |= PORTA_HOTPLUG_ENABLE |
+		   PORTB_HOTPLUG_ENABLE |
+		   PORTC_HOTPLUG_ENABLE;
 
 	DRM_DEBUG_KMS("Invert bit setting: hp_ctl:%x hp_port:%x\n",
 		      hotplug, enabled_irqs);
@@ -3198,7 +3204,6 @@ static void bxt_hpd_irq_setup(struct drm_i915_private *dev_priv)
 	 * For BXT invert bit has to be set based on AOB design
 	 * for HPD detection logic, update it based on VBT fields.
 	 */
-
 	if ((enabled_irqs & BXT_DE_PORT_HP_DDIA) &&
 	    intel_bios_is_port_hpd_inverted(dev_priv, PORT_A))
 		hotplug |= BXT_DDIA_HPD_INVERT;
@@ -3212,6 +3217,23 @@ static void bxt_hpd_irq_setup(struct drm_i915_private *dev_priv)
 	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
 }
 
+static void bxt_hpd_detection_setup(struct drm_i915_private *dev_priv)
+{
+	__bxt_hpd_detection_setup(dev_priv, BXT_DE_PORT_HOTPLUG_MASK);
+}
+
+static void bxt_hpd_irq_setup(struct drm_i915_private *dev_priv)
+{
+	u32 hotplug_irqs, enabled_irqs;
+
+	enabled_irqs = intel_hpd_enabled_irqs(dev_priv, hpd_bxt);
+	hotplug_irqs = BXT_DE_PORT_HOTPLUG_MASK;
+
+	bdw_update_port_irq(dev_priv, hotplug_irqs, enabled_irqs);
+
+	__bxt_hpd_detection_setup(dev_priv, enabled_irqs);
+}
+
 static void ibx_irq_postinstall(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -3227,6 +3249,12 @@ static void ibx_irq_postinstall(struct drm_device *dev)
 
 	gen5_assert_iir_is_zero(dev_priv, SDEIIR);
 	I915_WRITE(SDEIMR, ~mask);
+
+	if (HAS_PCH_IBX(dev_priv) || HAS_PCH_CPT(dev_priv) ||
+	    HAS_PCH_LPT(dev_priv))
+		; /* TODO: Enable HPD detection on older PCH platforms too */
+	else
+		spt_hpd_detection_setup(dev_priv);
 }
 
 static void gen5_gt_irq_postinstall(struct drm_device *dev)
@@ -3438,6 +3466,9 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
 
 	GEN5_IRQ_INIT(GEN8_DE_PORT_, ~de_port_masked, de_port_enables);
 	GEN5_IRQ_INIT(GEN8_DE_MISC_, ~de_misc_masked, de_misc_masked);
+
+	if (IS_GEN9_LP(dev_priv))
+		bxt_hpd_detection_setup(dev_priv);
 }
 
 static int gen8_irq_postinstall(struct drm_device *dev)