[Intel-gfx] [PATCH 11/20] drm/i915: Helper function to detach a scaler from a plane or crtc

[Chandra Konduru]

This function is called from commit path of a plane or crtc.
It programs scaler registers to detach (aka. unbinds) scaler
from requested plane or crtc if it isn't in use. It also resets
scaler_id in crtc/plane state.

v2:
-improved a log message (me)

v3:
-improved commentary (Matt)
-added a case where scaler id needs to be reset (me)

v4:
-changes made not to modify state in commit path (Matt)

Signed-off-by: Chandra Konduru <chandra.konduru at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |   29 +++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_drv.h     |    1 +
 2 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 603a2dc..8cf0d0e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2938,6 +2938,35 @@ unsigned long intel_plane_obj_offset(struct intel_plane *intel_plane,
 	return i915_gem_obj_ggtt_offset_view(obj, view);
 }
 
+/*
+ * This function detaches (aka. unbinds) unused scalers in hardware
+ */
+void skl_detach_scalers(struct intel_crtc *intel_crtc)
+{
+	struct drm_device *dev;
+	struct drm_i915_private *dev_priv;
+	struct intel_crtc_scaler_state *scaler_state;
+	int i;
+
+	if (!intel_crtc || !intel_crtc->config)
+		return;
+
+	dev = intel_crtc->base.dev;
+	dev_priv = dev->dev_private;
+	scaler_state = &intel_crtc->config->scaler_state;
+
+	/* loop through and disable scalers that aren't in use */
+	for (i = 0; i < scaler_state->num_scalers; i++) {
+		if (!scaler_state->scalers[i].in_use) {
+			I915_WRITE(SKL_PS_CTRL(intel_crtc->pipe, i), 0);
+			I915_WRITE(SKL_PS_WIN_POS(intel_crtc->pipe, i), 0);
+			I915_WRITE(SKL_PS_WIN_SZ(intel_crtc->pipe, i), 0);
+			DRM_DEBUG_KMS("CRTC:%d Disabled scaler id %u.%u\n",
+				intel_crtc->base.base.id, intel_crtc->pipe, i);
+		}
+	}
+}
+
 static void skylake_update_primary_plane(struct drm_crtc *crtc,
 					 struct drm_framebuffer *fb,
 					 int x, int y)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 1381d11..7bb4c44 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1146,6 +1146,7 @@ void intel_modeset_preclose(struct drm_device *dev, struct drm_file *file);
 int skl_update_scaler_users(struct intel_crtc *intel_crtc,
 	struct intel_crtc_state *crtc_state, struct intel_plane *intel_plane,
 	struct intel_plane_state *plane_state, int force_detach);
+void skl_detach_scalers(struct intel_crtc *intel_crtc);
 
 unsigned long intel_plane_obj_offset(struct intel_plane *intel_plane,
 				     struct drm_i915_gem_object *obj);
-- 
1.7.9.5