drm/i915: Make scaler_id check in check_crtc_state work for all gens

During check_crtc_state, scaler_id mispatch is being reported for HSW.
This is applicable for skl+ and not for HSW. It is introduced by
commit id:
    commit a1b2278e4dfcd2dbea85e319ebf73a6b7b2f180b
    Author: Chandra Konduru <chandra.konduru@intel.com>
    Date:   Tue Apr 7 15:28:45 2015 -0700

        drm/i915: skylake panel fitting using shared scalers

This patch will make sure that we leave scaler_id as 0 for platforms
before skl and set for skl+ only. This way scaler_id check during
check_crtc_state will pass for both prior to skl and skl+ platforms.

v2:
-Leave scaler_id as 0 for gen < 9 (Daniel)

Signed-off-by: Chandra Konduru <chandra.konduru@intel.com>
References: http://lists.freedesktop.org/archives/intel-gfx/2015-May/065741.html
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -9356,6 +9356,12 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 	}
 
 	pfit_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
+
+	if (INTEL_INFO(dev)->gen >= 9) {
+		pipe_config->scaler_state.scaler_id = -1;
+		pipe_config->scaler_state.scaler_users &= ~(1 << SKL_CRTC_INDEX);
+	}
+
 	if (intel_display_power_is_enabled(dev_priv, pfit_domain)) {
 		if (INTEL_INFO(dev)->gen == 9)
 			skylake_get_pfit_config(crtc, pipe_config);
@@ -9363,10 +9369,6 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 			ironlake_get_pfit_config(crtc, pipe_config);
 		else
 			MISSING_CASE(INTEL_INFO(dev)->gen);
-
-	} else {
-		pipe_config->scaler_state.scaler_id = -1;
-		pipe_config->scaler_state.scaler_users &= ~(1 << SKL_CRTC_INDEX);
 	}
 
 	if (IS_HASWELL(dev))
@@ -13266,8 +13268,8 @@ static struct drm_plane *intel_primary_plane_create(struct drm_device *dev,
 	primary->max_downscale = 1;
 	if (INTEL_INFO(dev)->gen >= 9) {
 		primary->can_scale = true;
+		state->scaler_id = -1;
 	}
-	state->scaler_id = -1;
 	primary->pipe = pipe;
 	primary->plane = pipe;
 	primary->check_plane = intel_check_primary_plane;
@@ -13449,7 +13451,6 @@ static struct drm_plane *intel_cursor_plane_create(struct drm_device *dev,
 	cursor->max_downscale = 1;
 	cursor->pipe = pipe;
 	cursor->plane = pipe;
-	state->scaler_id = -1;
 	cursor->check_plane = intel_check_cursor_plane;
 	cursor->commit_plane = intel_commit_cursor_plane;
 	cursor->disable_plane = intel_disable_cursor_plane;
@@ -13472,6 +13473,9 @@ static struct drm_plane *intel_cursor_plane_create(struct drm_device *dev,
 				state->base.rotation);
 	}
 
+	if (INTEL_INFO(dev)->gen >=9)
+		state->scaler_id = -1;
+
 	drm_plane_helper_add(&cursor->base, &intel_plane_helper_funcs);
 
 	return &cursor->base;