[Intel-gfx] [PATCH 3/3] drm/i915: Disable SAGV on bw init, to force QGV point recalculation

[Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>]

Problem is that on some platforms, we do get QGV point mask in wrong
state on boot. However driver assumes it is set to 0
(i.e all points allowed), however in reality we might get them all restricted,
causing issues.
Lets disable SAGV initially to force proper QGV point state.
If more QGV points are available, driver will recalculate and update
those then after next commit.

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
---
 drivers/gpu/drm/i915/display/intel_bw.c | 20 +++++++++++++++++++-
 drivers/gpu/drm/i915/display/intel_bw.h |  1 +
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index efd408e96e8a..f23f9f952de3 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -679,6 +679,9 @@ void intel_bw_init_hw(struct drm_i915_private *dev_priv)
 		tgl_get_bw_info(dev_priv, &tgl_sa_info);
 	else if (DISPLAY_VER(dev_priv) == 11)
 		icl_get_bw_info(dev_priv, &icl_sa_info);
+
+	if (DISPLAY_VER(dev_priv) < 14)
+		icl_force_disable_sagv(dev_priv);
 }
 
 static unsigned int intel_bw_crtc_num_active_planes(const struct intel_crtc_state *crtc_state)
@@ -844,7 +847,7 @@ static unsigned int icl_max_bw_qgv_point(struct drm_i915_private *i915,
 	return max_bw_point;
 }
 
-unsigned int icl_max_bw_psf_gv_point(struct drm_i915_private *i915)
+static unsigned int icl_max_bw_psf_gv_point(struct drm_i915_private *i915)
 {
 	unsigned int num_psf_gv_points = i915->display.bw.max[0].num_psf_gv_points;
 	unsigned int max_bw = 0;
@@ -863,6 +866,21 @@ unsigned int icl_max_bw_psf_gv_point(struct drm_i915_private *i915)
 	return max_bw_point;
 }
 
+int icl_force_disable_sagv(struct drm_i915_private *i915)
+{
+	unsigned int max_bw_qgv_point = icl_max_bw_qgv_point(i915, 0);
+	unsigned int max_bw_psf_gv_point = icl_max_bw_psf_gv_point(i915);
+	unsigned int qgv_points;
+	unsigned int psf_points;
+
+	qgv_points = BIT(max_bw_qgv_point);
+	psf_points = BIT(max_bw_psf_gv_point);
+
+	return icl_pcode_restrict_qgv_points(i915, ~(ICL_PCODE_REQ_QGV_PT(qgv_points) |
+					     ADLS_PCODE_REQ_PSF_PT(psf_points)) &
+					     icl_qgv_points_mask(i915));
+}
+
 static int mtl_find_qgv_points(struct drm_i915_private *i915,
 			       unsigned int data_rate,
 			       unsigned int num_active_planes,
diff --git a/drivers/gpu/drm/i915/display/intel_bw.h b/drivers/gpu/drm/i915/display/intel_bw.h
index 59cb4fc5db76..74acce1ef107 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.h
+++ b/drivers/gpu/drm/i915/display/intel_bw.h
@@ -74,5 +74,6 @@ int intel_bw_calc_min_cdclk(struct intel_atomic_state *state,
 			    bool *need_cdclk_calc);
 int intel_bw_min_cdclk(struct drm_i915_private *i915,
 		       const struct intel_bw_state *bw_state);
+int icl_force_disable_sagv(struct drm_i915_private *dev_priv);
 
 #endif /* __INTEL_BW_H__ */
-- 
2.37.3