drm/i915/dsc: make rc_model_size an encoder defined value

Move the initialization of the rc_model_size from the common code into
encoder code, allowing different encoders to specify the size according
to their needs. Keep using the hard coded value in the encoders for now
to make this a non-functional change.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/6843c4f6958619f7389180aa92fded7b9fdbb4ba.1607429866.git.jani.nikula@intel.com

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

@@ -1535,6 +1535,9 @@ static int gen11_dsi_dsc_compute_config(struct intel_encoder *encoder,
 
 	vdsc_cfg->convert_rgb = true;
 
+	/* FIXME: initialize from VBT */
+	vdsc_cfg->rc_model_size = DSC_RC_MODEL_SIZE_CONST;
+
 	ret = intel_dsc_compute_params(encoder, crtc_state);
 	if (ret)
 		return ret;

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

@@ -2289,6 +2289,14 @@ static int intel_dp_dsc_compute_params(struct intel_encoder *encoder,
 	u8 line_buf_depth;
 	int ret;
 
+	/*
+	 * RC_MODEL_SIZE is currently a constant across all configurations.
+	 *
+	 * FIXME: Look into using sink defined DPCD DP_DSC_RC_BUF_BLK_SIZE and
+	 * DP_DSC_RC_BUF_SIZE for this.
+	 */
+	vdsc_cfg->rc_model_size = DSC_RC_MODEL_SIZE_CONST;
+
 	ret = intel_dsc_compute_params(encoder, crtc_state);
 	if (ret)
 		return ret;

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

@@ -454,8 +454,6 @@ int intel_dsc_compute_params(struct intel_encoder *encoder,
 	else if (vdsc_cfg->bits_per_component == 12)
 		vdsc_cfg->mux_word_size = DSC_MUX_WORD_SIZE_12_BPC;
 
-	/* RC_MODEL_SIZE is a constant across all configurations */
-	vdsc_cfg->rc_model_size = DSC_RC_MODEL_SIZE_CONST;
 	/* InitialScaleValue is a 6 bit value with 3 fractional bits (U3.3) */
 	vdsc_cfg->initial_scale_value = (vdsc_cfg->rc_model_size << 3) /
 		(vdsc_cfg->rc_model_size - vdsc_cfg->initial_offset);