1 files changed, 13 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_hotplug_irq.c b/drivers/gpu/drm/i915/display/intel_hotplug_irq.c
index 2c4e946d5575..cb64c6f0ad1b 100644
--- a/drivers/gpu/drm/i915/display/intel_hotplug_irq.c
+++ b/drivers/gpu/drm/i915/display/intel_hotplug_irq.c
@@ -556,6 +556,7 @@ void xelpdp_pica_irq_handler(struct drm_i915_private *i915, u32 iir)
 
 void icp_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
 {
+	struct intel_display *display = &dev_priv->display;
 	u32 ddi_hotplug_trigger = pch_iir & SDE_DDI_HOTPLUG_MASK_ICP;
 	u32 tc_hotplug_trigger = pch_iir & SDE_TC_HOTPLUG_MASK_ICP;
 	u32 pin_mask = 0, long_mask = 0;
@@ -589,11 +590,12 @@ void icp_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
 		intel_hpd_irq_handler(dev_priv, pin_mask, long_mask);
 
 	if (pch_iir & SDE_GMBUS_ICP)
-		intel_gmbus_irq_handler(dev_priv);
+		intel_gmbus_irq_handler(display);
 }
 
 void spt_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
 {
+	struct intel_display *display = &dev_priv->display;
 	u32 hotplug_trigger = pch_iir & SDE_HOTPLUG_MASK_SPT &
 		~SDE_PORTE_HOTPLUG_SPT;
 	u32 hotplug2_trigger = pch_iir & SDE_PORTE_HOTPLUG_SPT;
@@ -625,7 +627,7 @@ void spt_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
 		intel_hpd_irq_handler(dev_priv, pin_mask, long_mask);
 
 	if (pch_iir & SDE_GMBUS_CPT)
-		intel_gmbus_irq_handler(dev_priv);
+		intel_gmbus_irq_handler(display);
 }
 
 void ilk_hpd_irq_handler(struct drm_i915_private *dev_priv, u32 hotplug_trigger)
@@ -849,10 +851,11 @@ static void icp_hpd_irq_setup(struct drm_i915_private *dev_priv)
 	enabled_irqs = intel_hpd_enabled_irqs(dev_priv, dev_priv->display.hotplug.pch_hpd);
 	hotplug_irqs = intel_hpd_hotplug_irqs(dev_priv, dev_priv->display.hotplug.pch_hpd);
 
-	if (INTEL_PCH_TYPE(dev_priv) <= PCH_TGP)
-		intel_uncore_write(&dev_priv->uncore, SHPD_FILTER_CNT, SHPD_FILTER_CNT_500_ADJ);
-	else
-		intel_uncore_write(&dev_priv->uncore, SHPD_FILTER_CNT, SHPD_FILTER_CNT_250);
+	/*
+	 * We reduce the value to 250us to be able to detect SHPD when an external display
+	 * is connected. This is also expected of us as stated in DP1.4a Table 3-4.
+	 */
+	intel_uncore_write(&dev_priv->uncore, SHPD_FILTER_CNT, SHPD_FILTER_CNT_250);
 
 	ibx_display_interrupt_update(dev_priv, hotplug_irqs, enabled_irqs);
 
@@ -1060,6 +1063,10 @@ static void mtp_hpd_irq_setup(struct drm_i915_private *i915)
 	enabled_irqs = intel_hpd_enabled_irqs(i915, i915->display.hotplug.pch_hpd);
 	hotplug_irqs = intel_hpd_hotplug_irqs(i915, i915->display.hotplug.pch_hpd);
 
+	/*
+	 * Use 250us here to align with the DP1.4a(Table 3-4) spec as to what the
+	 * SHPD_FILTER_CNT value should be.
+	 */
 	intel_de_write(i915, SHPD_FILTER_CNT, SHPD_FILTER_CNT_250);
 
 	mtp_hpd_invert(i915);