drm/i915: fix false positive "Unclaimed write" messages

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>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index f5b505a5b81e..f7aef97290bc 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1264,6 +1264,10 @@ 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 {                                                        \