drm/i915: Get slice height before computing rc params

We need slice height to calculate few RC parameters
hence assign slice height first.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210514153711.2359617-6-matthew.d.roper@intel.com

drivers/gpu/drm/i915/display/intel_dp.c

@@ -1153,10 +1153,6 @@ static int intel_dp_dsc_compute_params(struct intel_encoder *encoder,
 	 */
 	vdsc_cfg->rc_model_size = DSC_RC_MODEL_SIZE_CONST;
 
-	ret = intel_dsc_compute_params(encoder, crtc_state);
-	if (ret)
-		return ret;
-
 	/*
 	 * Slice Height of 8 works for all currently available panels. So start
 	 * with that if pic_height is an integral multiple of 8. Eventually add
@@ -1169,6 +1165,10 @@ static int intel_dp_dsc_compute_params(struct intel_encoder *encoder,
 	else
 		vdsc_cfg->slice_height = 2;
 
+	ret = intel_dsc_compute_params(encoder, crtc_state);
+	if (ret)
+		return ret;
+
 	vdsc_cfg->dsc_version_major =
 		(intel_dp->dsc_dpcd[DP_DSC_REV - DP_DSC_SUPPORT] &
 		 DP_DSC_MAJOR_MASK) >> DP_DSC_MAJOR_SHIFT;