[PATCH 06/10] drm/i915: print PCH poison interrupts

[Paulo Zanoni <przanoni@gmail.com>]

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

This is bad news and shouldn't be happening.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c |   29 +++++++++++++++++++++++++----
 drivers/gpu/drm/i915/i915_reg.h |    4 ++++
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 500fd65..10aec0e 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -665,6 +665,17 @@ static void ibx_irq_handler(struct drm_device *dev, u32 pch_iir)
 		DRM_DEBUG_DRIVER("PCH transcoder A underrun interrupt\n");
 }
 
+static void serr_int_handler(struct drm_device *dev)
+{
+	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+	u32 serr_int = I915_READ(SERR_INT);
+
+	if (serr_int & SERR_INT_POISON)
+		DRM_ERROR("PCH poison interrupt\n");
+
+	I915_WRITE(SERR_INT, serr_int);
+}
+
 static void cpt_irq_handler(struct drm_device *dev, u32 pch_iir)
 {
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
@@ -695,6 +706,9 @@ static void cpt_irq_handler(struct drm_device *dev, u32 pch_iir)
 			DRM_DEBUG_DRIVER("  pipe %c FDI IIR: 0x%08x\n",
 					 pipe_name(pipe),
 					 I915_READ(FDI_RX_IIR(pipe)));
+
+	if (pch_iir & SDE_ERROR_CPT)
+		serr_int_handler(dev);
 }
 
 static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
@@ -1943,14 +1957,19 @@ static void ibx_irq_postinstall(struct drm_device *dev)
 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 	u32 mask;
 
-	if (HAS_PCH_IBX(dev))
+	if (HAS_PCH_IBX(dev)) {
 		mask = SDE_HOTPLUG_MASK |
 		       SDE_GMBUS |
-		       SDE_AUX_MASK;
-	else
+		       SDE_AUX_MASK |
+		       SDE_POISON;
+	} else {
 		mask = SDE_HOTPLUG_MASK_CPT |
 		       SDE_GMBUS_CPT |
-		       SDE_AUX_MASK_CPT;
+		       SDE_AUX_MASK_CPT |
+		       SDE_ERROR_CPT;
+
+		I915_WRITE(SERR_INT, I915_READ(SERR_INT));
+	}
 
 	I915_WRITE(SDEIIR, I915_READ(SDEIIR));
 	I915_WRITE(SDEIMR, ~mask);
@@ -2180,6 +2199,8 @@ static void ironlake_irq_uninstall(struct drm_device *dev)
 	I915_WRITE(SDEIMR, 0xffffffff);
 	I915_WRITE(SDEIER, 0x0);
 	I915_WRITE(SDEIIR, I915_READ(SDEIIR));
+	if (HAS_PCH_CPT(dev) || HAS_PCH_LPT(dev))
+		I915_WRITE(SERR_INT, I915_READ(SERR_INT));
 }
 
 static void i8xx_irq_preinstall(struct drm_device * dev)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 663b5c1..9cd59f7 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3528,6 +3528,7 @@
 				 SDE_PORTC_HOTPLUG_CPT |	\
 				 SDE_PORTB_HOTPLUG_CPT)
 #define SDE_GMBUS_CPT		(1 << 17)
+#define SDE_ERROR_CPT		(1 << 16)
 #define SDE_AUDIO_CP_REQ_C_CPT	(1 << 10)
 #define SDE_AUDIO_CP_CHG_C_CPT	(1 << 9)
 #define SDE_FDI_RXC_CPT		(1 << 8)
@@ -3552,6 +3553,9 @@
 #define SDEIIR  0xc4008
 #define SDEIER  0xc400c
 
+#define SERR_INT		0xc4040
+#define  SERR_INT_POISON	(1 << 31)
+
 /* digital port hotplug */
 #define PCH_PORT_HOTPLUG        0xc4030		/* SHOTPLUG_CTL */
 #define PORTD_HOTPLUG_ENABLE            (1 << 20)
-- 
1.7.10.4