drm/radeon/kms: fix DP training for DPEncoderService revision bigger than 1.1

commit 5a96a899 upstream.

DPEncoderService newer than 1.1 can't properly program the DP (display port)
link training. When facing such version use the DIGxEncoderControl method
instead. Fix DP link training on some R7XX.
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/gpu/drm/radeon/atombios_dp.c

@@ -627,6 +627,7 @@ struct radeon_dp_link_train_info {
 	u8 train_set[4];
 	u8 link_status[DP_LINK_STATUS_SIZE];
 	u8 tries;
+	bool use_dpencoder;
 };
 
 static void radeon_dp_update_vs_emph(struct radeon_dp_link_train_info *dp_info)
@@ -646,7 +647,7 @@ static void radeon_dp_set_tp(struct radeon_dp_link_train_info *dp_info, int tp)
 	int rtp = 0;
 
 	/* set training pattern on the source */
-	if (ASIC_IS_DCE4(dp_info->rdev)) {
+	if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder) {
 		switch (tp) {
 		case DP_TRAINING_PATTERN_1:
 			rtp = ATOM_ENCODER_CMD_DP_LINK_TRAINING_PATTERN1;
@@ -706,7 +707,7 @@ static int radeon_dp_link_train_init(struct radeon_dp_link_train_info *dp_info)
 	radeon_write_dpcd_reg(dp_info->radeon_connector, DP_LINK_BW_SET, tmp);
 
 	/* start training on the source */
-	if (ASIC_IS_DCE4(dp_info->rdev))
+	if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder)
 		atombios_dig_encoder_setup(dp_info->encoder,
 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_START, 0);
 	else
@@ -731,7 +732,7 @@ static int radeon_dp_link_train_finish(struct radeon_dp_link_train_info *dp_info
 			      DP_TRAINING_PATTERN_DISABLE);
 
 	/* disable the training pattern on the source */
-	if (ASIC_IS_DCE4(dp_info->rdev))
+	if (ASIC_IS_DCE4(dp_info->rdev) || !dp_info->use_dpencoder)
 		atombios_dig_encoder_setup(dp_info->encoder,
 					   ATOM_ENCODER_CMD_DP_LINK_TRAINING_COMPLETE, 0);
 	else
@@ -869,7 +870,8 @@ void radeon_dp_link_train(struct drm_encoder *encoder,
 	struct radeon_connector *radeon_connector;
 	struct radeon_connector_atom_dig *dig_connector;
 	struct radeon_dp_link_train_info dp_info;
- 	u8 tmp;
+	int index;
+	u8 tmp, frev, crev;
 
 	if (!radeon_encoder->enc_priv)
 		return;
@@ -884,6 +886,18 @@ void radeon_dp_link_train(struct drm_encoder *encoder,
 	    (dig_connector->dp_sink_type != CONNECTOR_OBJECT_ID_eDP))
 		return;
 
+	/* DPEncoderService newer than 1.1 can't program properly the
+	 * training pattern. When facing such version use the
+	 * DIGXEncoderControl (X== 1 | 2)
+	 */
+	dp_info.use_dpencoder = true;
+	index = GetIndexIntoMasterTable(COMMAND, DPEncoderService);
+	if (atom_parse_cmd_header(rdev->mode_info.atom_context, index, &frev, &crev)) {
+		if (crev > 1) {
+			dp_info.use_dpencoder = false;
+		}
+	}
+
 	dp_info.enc_id = 0;
 	if (dig->dig_encoder)
 		dp_info.enc_id |= ATOM_DP_CONFIG_DIG2_ENCODER;