[PATCH] drm/i915: fix assert_cursor on BDW

[Paulo Zanoni <przanoni@gmail.com>]

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

We need to read the correct register, not a register that doesn't exist
and will trigger "Unclaimed register" messages when we touch it.

Also rearrange the checks in an attempt to prevent this error from
happening again.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

This patch is untested, but the "Uncalimed register" message is real, as long as
we have the patch to print them.

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f19e6ea..2e05d1e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1095,12 +1095,13 @@ static void assert_cursor(struct drm_i915_private *dev_priv,
 	struct drm_device *dev = dev_priv->dev;
 	bool cur_state;
 
-	if (IS_IVYBRIDGE(dev) || IS_HASWELL(dev))
-		cur_state = I915_READ(CURCNTR_IVB(pipe)) & CURSOR_MODE;
-	else if (IS_845G(dev) || IS_I865G(dev))
+
+	if (IS_845G(dev) || IS_I865G(dev))
 		cur_state = I915_READ(_CURACNTR) & CURSOR_ENABLE;
-	else
+	else if (INTEL_INFO(dev)->gen <= 6 || IS_VALLEYVIEW(dev))
 		cur_state = I915_READ(CURCNTR(pipe)) & CURSOR_MODE;
+	else
+		cur_state = I915_READ(CURCNTR_IVB(pipe)) & CURSOR_MODE;
 
 	WARN(cur_state != state,
 	     "cursor on pipe %c assertion failure (expected %s, current %s)\n",
-- 
1.8.5.3