[Intel-gfx] [PATCH 4/5] drm/i915: Add a FIXME about FBC vs. fence. 90/270 degree rotation

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Currently we're pinning the fence for the rotated GTT view. That doesn't
acually make any sense since the fence is used only for the FBC GTT
tracking. For that we would want the fence for the normal GTT view
instead of the rotated view. Too lazy to fix this now so just add a
FIXME.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3b7021b39fdf..25050bfce5d1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2202,6 +2202,12 @@ intel_pin_and_fence_fb_obj(const struct drm_framebuffer *fb,
 
 	atomic_inc(&dev_priv->gpu_error.pending_fb_pin);
 
+	/*
+	 * FIXME presumably with FBC and 90/270 degree rotation we
+	 * should pin the fence on the normal GTT view, and tell FBC
+	 * to monitor that one instead of the rotated view. Would
+	 * need changes to the FBC fence Y offset as well.
+	 */
 	vma = i915_gem_object_pin_to_display_plane(obj, alignment,
 						   needs_fence, &view);
 	if (IS_ERR(vma))
-- 
2.13.6