[Intel-gfx] [PATCH v3 2/8] drm/i915: update the QGV point frequency calculations

Vinod Govindapillai vinod.govindapillai at intel.com
Thu Apr 27 15:00:10 UTC 2023


>From MTL onwwards, pcode locks the QGV point based on peak BW of
the intended QGV point passed by the driver. So the peak BW
calculation must match the value expected by the pcode. Update
the calculations as per the Bspec.

Bspec: 64636

Signed-off-by: Vinod Govindapillai <vinod.govindapillai at intel.com>
---
 drivers/gpu/drm/i915/display/intel_bw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index ab405c48ca3a..25ae4e5834d3 100644
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -182,7 +182,7 @@ static int mtl_read_qgv_point_info(struct drm_i915_private *dev_priv,
 	val2 = intel_uncore_read(&dev_priv->uncore,
 				 MTL_MEM_SS_INFO_QGV_POINT_HIGH(point));
 	dclk = REG_FIELD_GET(MTL_DCLK_MASK, val);
-	sp->dclk = DIV_ROUND_UP((16667 * dclk), 1000);
+	sp->dclk = (16667 * dclk + 500) / 1000;
 	sp->t_rp = REG_FIELD_GET(MTL_TRP_MASK, val);
 	sp->t_rcd = REG_FIELD_GET(MTL_TRCD_MASK, val);
 
-- 
2.34.1



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