[Intel-gfx] [PATCH v1 1/3] drm/i915: Decouple cdclk calculation from modeset checks

[Stanislav Lisovskiy]

We need to calculate cdclk after watermarks/ddb has been calculated
as with recent hw CDCLK needs to be adjusted accordingly to DBuf
requirements, which is not possible with current code organization.

Setting CDCLK according to DBuf BW requirements and not just rejecting
if it doesn't satisfy BW requirements, will allow us to save power when
it is possible and gain additional bandwidth when it's needed - i.e
boosting both our power management and perfomance capabilities.

This patch is preparation for that, first we now extract modeset
calculation from modeset checks, in order to call it after wm/ddb
has been calculated.

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 22 ++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 8f23c4d51c33..cdff3054b344 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -14542,6 +14542,14 @@ static int intel_modeset_checks(struct intel_atomic_state *state)
 			return ret;
 	}
 
+	return 0;
+}
+
+static int intel_modeset_cdclk(struct intel_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	int ret;
+
 	ret = intel_modeset_calc_cdclk(state);
 	if (ret)
 		return ret;
@@ -14879,10 +14887,6 @@ static int intel_atomic_check(struct drm_device *dev,
 			goto fail;
 	}
 
-	ret = intel_atomic_check_crtcs(state);
-	if (ret)
-		goto fail;
-
 	intel_fbc_choose_crtc(dev_priv, state);
 	ret = calc_watermark_data(state);
 	if (ret)
@@ -14892,6 +14896,16 @@ static int intel_atomic_check(struct drm_device *dev,
 	if (ret)
 		goto fail;
 
+	if (any_ms) {
+		ret = intel_modeset_cdclk(state);
+		if (ret)
+			goto fail;
+	}
+
+	ret = intel_atomic_check_crtcs(state);
+	if (ret)
+		goto fail;
+
 	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
 					    new_crtc_state, i) {
 		if (!needs_modeset(new_crtc_state) &&
-- 
2.24.1.485.gad05a3d8e5