[Intel-gfx] [PATCH v3 11/11] drm/i915/mtl: Do not update GV point, mask value

[Radhakrishna Sripada]

Display 14 and future platforms do not directly communicate to Pcode
via mailbox the SAGV bandwidth information. PM Demand registers are
used to communicate display power requirements to the PUnit which would
include GV point and mask value.

Skip programming GV point and mask values through legacy pcode mailbox
interface.

Bspec: 64636
Cc: Matt Roper <matthew.d.roper at intel.com>
Original Author: Caz Yokoyama
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index b19a1ecb010e..69efd613bbde 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3923,6 +3923,14 @@ void intel_sagv_pre_plane_update(struct intel_atomic_state *state)
 {
 	struct drm_i915_private *i915 = to_i915(state->base.dev);
 
+	/*
+	 * No need to update mask value/restrict because
+	 * "Pcode only wants to use GV bandwidth value, not the mask value."
+	 * for DISPLAY_VER() >= 14.
+	 */
+	if (DISPLAY_VER(i915) >= 14)
+		return;
+
 	/*
 	 * Just return if we can't control SAGV or don't have it.
 	 * This is different from situation when we have SAGV but just can't
@@ -3943,6 +3951,16 @@ void intel_sagv_post_plane_update(struct intel_atomic_state *state)
 {
 	struct drm_i915_private *i915 = to_i915(state->base.dev);
 
+	/*
+	 * No need to update mask value/restrict because
+	 * "Pcode only wants to use GV bandwidth value, not the mask value."
+	 * for DISPLAY_VER() >= 14.
+	 *
+	 * GV bandwidth will be set by intel_pmdemand_post_plane_update()
+	 */
+	if (DISPLAY_VER(i915) >= 14)
+		return;
+
 	/*
 	 * Just return if we can't control SAGV or don't have it.
 	 * This is different from situation when we have SAGV but just can't
-- 
2.25.1