[PATCH 03/19] drm/i915: use GEN8_IRQ_INIT on GEN5

[Paulo Zanoni <przanoni@gmail.com>]

From: Paulo Zanoni <paulo.r.zanoni@intel.com>

And rename is to GEN5_IRQ_INIT.

We have discussed doing equivalent changes on July 2013, and I even
sent a patch series for this: "[PATCH 00/15] Unify interrupt register
init/reset". Now that the BDW code was merged, I have one more
argument in favor of these changes.

Here's what really changes with the Gen 5 IRQ init code:
  - We now clear the IIR registers at preinstall (they are also
    cleared at postinstall, but we will change that later).
  - We have an additional POSTING_READ at the IMR register.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 49 +++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 8bbaa3c..8fdbb5b 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -80,12 +80,30 @@ static const u32 hpd_status_i915[] = { /* i915 and valleyview are the same */
 	[HPD_PORT_D] = PORTD_HOTPLUG_INT_STATUS
 };
 
+/*
+ * IIR can theoretically queue up two events. Be paranoid.
+ * Also, make sure callers of these macros have something equivalent to a
+ * POSTING_READ on the IIR register.
+ * */
+#define GEN8_IRQ_INIT_NDX(type, which) do { \
+	I915_WRITE(GEN8_##type##_IMR(which), 0xffffffff); \
+	POSTING_READ(GEN8_##type##_IMR(which)); \
+	I915_WRITE(GEN8_##type##_IER(which), 0); \
+	I915_WRITE(GEN8_##type##_IIR(which), 0xffffffff); \
+	POSTING_READ(GEN8_##type##_IIR(which)); \
+	I915_WRITE(GEN8_##type##_IIR(which), 0xffffffff); \
+} while (0)
+
 #define GEN5_IRQ_INIT(type) do { \
 	I915_WRITE(type##IMR, 0xffffffff); \
+	POSTING_READ(type##IMR); \
 	I915_WRITE(type##IER, 0); \
-	POSTING_READ(type##IER); \
+	I915_WRITE(type##IIR, 0xffffffff); \
+	POSTING_READ(type##IIR); \
+	I915_WRITE(type##IIR, 0xffffffff); \
 } while (0)
 
+
 /* For display hotplug interrupt */
 static void
 ironlake_enable_display_irq(drm_i915_private_t *dev_priv, u32 mask)
@@ -2621,6 +2639,7 @@ static void gen5_gt_irq_preinstall(struct drm_device *dev)
 	GEN5_IRQ_INIT(GT);
 	if (INTEL_INFO(dev)->gen >= 6)
 		GEN5_IRQ_INIT(GEN6_PM);
+	POSTING_READ(GTIIR);
 }
 
 /* drm_dma.h hooks
@@ -2675,25 +2694,6 @@ static void gen8_irq_preinstall(struct drm_device *dev)
 	I915_WRITE(GEN8_MASTER_IRQ, 0);
 	POSTING_READ(GEN8_MASTER_IRQ);
 
-	/* IIR can theoretically queue up two events. Be paranoid */
-#define GEN8_IRQ_INIT_NDX(type, which) do { \
-		I915_WRITE(GEN8_##type##_IMR(which), 0xffffffff); \
-		POSTING_READ(GEN8_##type##_IMR(which)); \
-		I915_WRITE(GEN8_##type##_IER(which), 0); \
-		I915_WRITE(GEN8_##type##_IIR(which), 0xffffffff); \
-		POSTING_READ(GEN8_##type##_IIR(which)); \
-		I915_WRITE(GEN8_##type##_IIR(which), 0xffffffff); \
-	} while (0)
-
-#define GEN8_IRQ_INIT(type) do { \
-		I915_WRITE(GEN8_##type##_IMR, 0xffffffff); \
-		POSTING_READ(GEN8_##type##_IMR); \
-		I915_WRITE(GEN8_##type##_IER, 0); \
-		I915_WRITE(GEN8_##type##_IIR, 0xffffffff); \
-		POSTING_READ(GEN8_##type##_IIR); \
-		I915_WRITE(GEN8_##type##_IIR, 0xffffffff); \
-	} while (0)
-
 	GEN8_IRQ_INIT_NDX(GT, 0);
 	GEN8_IRQ_INIT_NDX(GT, 1);
 	GEN8_IRQ_INIT_NDX(GT, 2);
@@ -2703,12 +2703,9 @@ static void gen8_irq_preinstall(struct drm_device *dev)
 		GEN8_IRQ_INIT_NDX(DE_PIPE, pipe);
 	}
 
-	GEN8_IRQ_INIT(DE_PORT);
-	GEN8_IRQ_INIT(DE_MISC);
-	GEN8_IRQ_INIT(PCU);
-#undef GEN8_IRQ_INIT
-#undef GEN8_IRQ_INIT_NDX
-
+	GEN5_IRQ_INIT(GEN8_DE_PORT_);
+	GEN5_IRQ_INIT(GEN8_DE_MISC_);
+	GEN5_IRQ_INIT(GEN8_PCU_);
 	POSTING_READ(GEN8_PCU_IIR);
 
 	ibx_irq_preinstall(dev);
-- 
1.8.4.2