Userspace can easily hit this and does since Ville added a new evil
igt testcase in:
commit 069e35e0fc3785faa562adcfd2dd7bbed4cb1dea
Author: Ville Syrj?l? <ville.syrjala at linux.intel.com>
Date: Mon Mar 4 15:34:06 2013 +0200
kms_flip: Add flip-vs-bad-tiling test
Cc: Ville Syrj?l? <ville.syrjala at linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
drivers/gpu/drm/i915/intel_display.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 1b2c744..7ac7de6 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1907,8 +1907,10 @@ intel_pin_and_fence_fb_obj(struct drm_device *dev,
alignment = 0;
break;
case I915_TILING_Y:
- /* FIXME: Is this true? */
- DRM_ERROR("Y tiled not allowed for scan out buffers\n");
+ /* Despite that we check this in framebuffer init userspace can
+ * scre us over and change the tiling after the fact. Only
+ * pinned buffers can't change their tiling. */
+ DRM_DEBUG_DRIVER("Y tiled not allowed for scan out buffers\n");
return -EINVAL;
default:
BUG();
--
1.7.10.4
