[PATCH] drm/i915/display: Disable AuxCCS framebuffers if built for Xe

[Juha-Pekka Heikkila]

AuxCCS framebuffers don't work on Xe driver hence disable them
from plane capabilities until they are fixed. FlatCCS framebuffers
work and they are left enabled. CCS is left untouched for i915
driver.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/933
Signed-off-by: Juha-Pekka Heikkila <juhapekka.heikkila at gmail.com>
---
Let's try adding those ifdefs as IS_ENABLED(I915) will result in
warnings from checkpatch and there was wishes not to break
universal plane into smaller parts. IS_ENABLED(CONFIG_I915) is
always true when building both Xe and i915.

 .../gpu/drm/i915/display/skl_universal_plane.c  | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c
index e941e2e4fd14..7e0a7283d01d 100644
--- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
+++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
@@ -2283,6 +2283,15 @@ static bool gen12_plane_has_mc_ccs(struct drm_i915_private *i915,
 	return plane_id < PLANE_SPRITE4;
 }
 
+static bool running_on_i915(void)
+{
+#ifdef I915
+	return true;
+#else
+	return false;
+#endif
+}
+
 static u8 skl_get_plane_caps(struct drm_i915_private *i915,
 			     enum pipe pipe, enum plane_id plane_id)
 {
@@ -2295,6 +2304,14 @@ static u8 skl_get_plane_caps(struct drm_i915_private *i915,
 	if (HAS_4TILE(i915))
 		caps |= INTEL_PLANE_CAP_TILING_4;
 
+	/*
+	 * FIXME: Below if(running_on_i915()..) is because Xe driver
+	 * can't use AuxCCS framebuffers. Once they are fixed this need to be
+	 * removed.
+	 */
+	if (!running_on_i915() && !HAS_FLAT_CCS(i915))
+		return caps;
+
 	if (skl_plane_has_rc_ccs(i915, pipe, plane_id)) {
 		caps |= INTEL_PLANE_CAP_CCS_RC;
 		if (DISPLAY_VER(i915) >= 12)
-- 
2.25.1