[Intel-gfx] [PATCH 08/25] drm/i915: Check panel fitting state before enabling fbc

[ville.syrjala at linux.intel.com]

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

WaFbcOnlyForNativeModeOnLFP:ctg says we need to disable fbc when panel
fitting is enabled on g4x.

On ilk we need to disable fbc if panel fitter is downscaling. Upscaling
is apparently OK.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 07fa149..cdadf6e 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -556,6 +556,32 @@ static bool intel_fbc2_possible(struct intel_crtc *crtc)
 		return false;
 	}
 
+	if (IS_G4X(dev)) {
+		/* WaFbcOnlyForNativeModeOnLFP:ctg */
+		if (crtc->config.gmch_pfit.control) {
+			DRM_DEBUG("FBC pipe %c, plane %c: panel fitter enabled\n",
+				  pipe_name(crtc->pipe), plane_name(crtc->plane));
+			return false;
+		}
+	}
+
+	if (IS_GEN5(dev) && crtc->config.pch_pfit.enabled) {
+		uint32_t pfit_w, pfit_h;
+
+		pfit_w = crtc->config.pch_pfit.size >> 16;
+		pfit_h = crtc->config.pch_pfit.size & 0xFFFF;
+
+		/* FBC not allowed with panel fitter downscaling */
+		if (crtc->config.pipe_src_w > pfit_w ||
+		    crtc->config.pipe_src_h > pfit_h) {
+			DRM_DEBUG("FBC pipe %c, plane %c: panel fitter downscaling\n",
+				  pipe_name(crtc->pipe), plane_name(crtc->plane));
+			return false;
+		}
+
+		/* TODO: PF-ID is also disallowed */
+	}
+
 	if (!crtc->primary_enabled) {
 		DRM_DEBUG("FBC pipe %c, plane %c: primary plane disabled\n",
 			  pipe_name(crtc->pipe), plane_name(crtc->plane));
-- 
1.8.5.5