[PATCH 04/10] drm/i915: fix false positive "Unclaimed write" messages

[Paulo Zanoni <przanoni@gmail.com>]

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

We don't check if the "unclaimed register" bit is set before we call
writel, so if it was already set before, we might print a misleading
message about "unclaimed write" on the wrong register.

This patch makes us check the unclaimed bit before the writel, so we
can print a new "Unknown unclaimed register before writing to %x"
message.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 418d17c..88c44ad 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1251,6 +1251,10 @@ void i915_write##x(struct drm_i915_private *dev_priv, u32 reg, u##x val) { \
 	} \
 	if (IS_GEN5(dev_priv->dev)) \
 		ilk_dummy_write(dev_priv); \
+	if (IS_HASWELL(dev_priv->dev) && (I915_READ_NOTRACE(GEN7_ERR_INT) & ERR_INT_MMIO_UNCLAIMED)) { \
+		DRM_ERROR("Unknown unclaimed register before writing to %x\n", reg); \
+		I915_WRITE_NOTRACE(GEN7_ERR_INT, ERR_INT_MMIO_UNCLAIMED); \
+	} \
 	if (IS_VALLEYVIEW(dev_priv->dev) && IS_DISPLAYREG(reg)) { \
 		write##y(val, dev_priv->regs + reg + 0x180000);		\
 	} else {							\
-- 
1.7.11.7