[PATCH 7/7] drm/i915: there's no PIPESTAT on HAS_PCH_SPLIT platforms

[Paulo Zanoni <przanoni@gmail.com>]

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

So don't read it when capturing the error state. This solves
"unclaimed register" messages on Haswell when we have a GPU hang.

V2: Check for HAS_PCH_SPLIT instead of Gen5+ because VLV still has
this register.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 5fc178e..3c2b05c 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1387,8 +1387,9 @@ static void i915_capture_error_state(struct drm_device *dev)
 	else if (INTEL_INFO(dev)->gen == 6)
 		error->forcewake = I915_READ(FORCEWAKE);
 
-	for_each_pipe(pipe)
-		error->pipestat[pipe] = I915_READ(PIPESTAT(pipe));
+	if (!HAS_PCH_SPLIT(dev))
+		for_each_pipe(pipe)
+			error->pipestat[pipe] = I915_READ(PIPESTAT(pipe));
 
 	if (INTEL_INFO(dev)->gen >= 6) {
 		error->error = I915_READ(ERROR_GEN6);
-- 
1.7.10.4