drm/i915/bios: intel_bios_dp_boost_level()

Don't access i915->vbt.ddi_port_info[] directly.
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fb8645cecadbc4ebeea1c0de94cb3116a769d9bf.1579270868.git.jani.nikula@intel.com

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

@@ -2578,3 +2578,10 @@ int intel_bios_hdmi_level_shift(struct intel_encoder *encoder)
 
 	return info->hdmi_level_shift_set ? info->hdmi_level_shift : -1;
 }
+
+int intel_bios_dp_boost_level(struct intel_encoder *encoder)
+{
+	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
+
+	return i915->vbt.ddi_port_info[encoder->port].dp_boost_level;
+}

drivers/gpu/drm/i915/display/intel_bios.h

@@ -249,5 +249,6 @@ bool intel_bios_get_dsc_params(struct intel_encoder *encoder,
 			       int dsc_max_bpc);
 int intel_bios_max_tmds_clock(struct intel_encoder *encoder);
 int intel_bios_hdmi_level_shift(struct intel_encoder *encoder);
+int intel_bios_dp_boost_level(struct intel_encoder *encoder);
 
 #endif /* _INTEL_BIOS_H_ */

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

@@ -1022,8 +1022,7 @@ static void intel_prepare_dp_ddi_buffers(struct intel_encoder *encoder,
 							      &n_entries);
 
 	/* If we're boosting the current, set bit 31 of trans1 */
-	if (IS_GEN9_BC(dev_priv) &&
-	    dev_priv->vbt.ddi_port_info[port].dp_boost_level)
+	if (IS_GEN9_BC(dev_priv) && intel_bios_dp_boost_level(encoder))
 		iboost_bit = DDI_BUF_BALANCE_LEG_ENABLE;
 
 	for (i = 0; i < n_entries; i++) {
@@ -2344,7 +2343,7 @@ static void skl_ddi_set_iboost(struct intel_encoder *encoder,
 	if (type == INTEL_OUTPUT_HDMI)
 		iboost = dev_priv->vbt.ddi_port_info[port].hdmi_boost_level;
 	else
-		iboost = dev_priv->vbt.ddi_port_info[port].dp_boost_level;
+		iboost = intel_bios_dp_boost_level(encoder);
 
 	if (iboost == 0) {
 		const struct ddi_buf_trans *ddi_translations;