drm/i915: All members of gen4 have hotplug, so unconditionally enable its irq

Also as we set the HOTPLUG_EN to 0 during pre-install, we can simply set
it during post-install, and nor do we wish to enable unwanted hotplug
events.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -2320,10 +2320,8 @@ static void i965_irq_preinstall(struct drm_device * dev)
 
 	atomic_set(&dev_priv->irq_received, 0);
 
-	if (I915_HAS_HOTPLUG(dev)) {
 	I915_WRITE(PORT_HOTPLUG_EN, 0);
 	I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));
-	}
 
 	I915_WRITE(HWSTAM, 0xeffe);
 	for_each_pipe(pipe)
@@ -2336,11 +2334,13 @@ static void i965_irq_preinstall(struct drm_device * dev)
 static int i965_irq_postinstall(struct drm_device *dev)
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+	u32 hotplug_en;
 	u32 enable_mask;
 	u32 error_mask;
 
 	/* Unmask the interrupts that we always want on. */
 	dev_priv->irq_mask = ~(I915_ASLE_INTERRUPT |
+			       I915_DISPLAY_PORT_INTERRUPT |
 			       I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
 			       I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
 			       I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
@@ -2356,13 +2356,6 @@ static int i965_irq_postinstall(struct drm_device *dev)
 	dev_priv->pipestat[0] = 0;
 	dev_priv->pipestat[1] = 0;
 
-	if (I915_HAS_HOTPLUG(dev)) {
-		/* Enable in IER... */
-		enable_mask |= I915_DISPLAY_PORT_INTERRUPT;
-		/* and unmask in IMR */
-		dev_priv->irq_mask &= ~I915_DISPLAY_PORT_INTERRUPT;
-	}
-
 	/*
 	 * Enable some error detection, note the instruction error mask
 	 * bit is reserved, so we leave it masked.
@@ -2382,10 +2375,8 @@ static int i965_irq_postinstall(struct drm_device *dev)
 	I915_WRITE(IER, enable_mask);
 	POSTING_READ(IER);
 
-	if (I915_HAS_HOTPLUG(dev)) {
-		u32 hotplug_en = I915_READ(PORT_HOTPLUG_EN);
-
-		/* Note HDMI and DP share bits */
+	/* Note HDMI and DP share hotplug bits */
+	hotplug_en = 0;
 	if (dev_priv->hotplug_supported_mask & HDMIB_HOTPLUG_INT_STATUS)
 		hotplug_en |= HDMIB_HOTPLUG_INT_EN;
 	if (dev_priv->hotplug_supported_mask & HDMIC_HOTPLUG_INT_STATUS)
@@ -2411,7 +2402,6 @@ static int i965_irq_postinstall(struct drm_device *dev)
 	/* Ignore TV since it's buggy */
 
 	I915_WRITE(PORT_HOTPLUG_EN, hotplug_en);
-	}
 
 	intel_opregion_enable_asle(dev);
 
@@ -2469,8 +2459,7 @@ static irqreturn_t i965_irq_handler(DRM_IRQ_ARGS)
 		ret = IRQ_HANDLED;
 
 		/* Consume port.  Then clear IIR or we'll miss events */
-		if ((I915_HAS_HOTPLUG(dev)) &&
-		    (iir & I915_DISPLAY_PORT_INTERRUPT)) {
+		if (iir & I915_DISPLAY_PORT_INTERRUPT) {
 			u32 hotplug_status = I915_READ(PORT_HOTPLUG_STAT);
 
 			DRM_DEBUG_DRIVER("hotplug event received, stat 0x%08x\n",
@@ -2543,10 +2532,8 @@ static void i965_irq_uninstall(struct drm_device * dev)
 	if (!dev_priv)
 		return;
 
-	if (I915_HAS_HOTPLUG(dev)) {
 	I915_WRITE(PORT_HOTPLUG_EN, 0);
 	I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));
-	}
 
 	I915_WRITE(HWSTAM, 0xffffffff);
 	for_each_pipe(pipe)