drm: extract dp link train delay functions from radeon

This requires a few changes since that dpcd value is above the
range currently cached by radeon. I've check the dp specs, and
above 0xf there's a big gap and nothing that looks like we should
cache it while a given device is plugged in. It's also the same value
that i915.ko uses.

Hence extend the various dpcd arrays in the radeon driver, use
proper symbolic constants where applicable (one place overallocated
the dpcd array to 25 bytes). Then also drop the rd_interval cache -
radeon_dp_link_train_init re-reads the dpcd block, so the values we'll
consume in train_cr and train_ce will always be fresh.

To avoid needless diff-churn, #define the old size of dpcd as the new
one and keep it around.

v2: Alex Deucher noticed one place where I've forgotten to replace 8
with DP_RECEIVER_CAP_SIZE.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index 5ad8bfa..5e23ab2 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -34,7 +34,7 @@
 
 /* move these to drm_dp_helper.c/h */
 #define DP_LINK_CONFIGURATION_SIZE 9
-#define DP_DPCD_SIZE	           8
+#define DP_DPCD_SIZE DP_RECEIVER_CAP_SIZE
 
 static char *voltage_names[] = {
         "0.4V", "0.6V", "0.8V", "1.2V"
@@ -478,14 +478,15 @@
 bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
 {
 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
-	u8 msg[25];
+	u8 msg[DP_DPCD_SIZE];
 	int ret, i;
 
-	ret = radeon_dp_aux_native_read(radeon_connector, DP_DPCD_REV, msg, 8, 0);
+	ret = radeon_dp_aux_native_read(radeon_connector, DP_DPCD_REV, msg,
+					DP_DPCD_SIZE, 0);
 	if (ret > 0) {
-		memcpy(dig_connector->dpcd, msg, 8);
+		memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
 		DRM_DEBUG_KMS("DPCD: ");
-		for (i = 0; i < 8; i++)
+		for (i = 0; i < DP_DPCD_SIZE; i++)
 			DRM_DEBUG_KMS("%02x ", msg[i]);
 		DRM_DEBUG_KMS("\n");
 
@@ -604,9 +605,8 @@
 	int enc_id;
 	int dp_clock;
 	int dp_lane_count;
-	int rd_interval;
 	bool tp3_supported;
-	u8 dpcd[8];
+	u8 dpcd[DP_RECEIVER_CAP_SIZE];
 	u8 train_set[4];
 	u8 link_status[DP_LINK_STATUS_SIZE];
 	u8 tries;
@@ -748,10 +748,7 @@
 	dp_info->tries = 0;
 	voltage = 0xff;
 	while (1) {
-		if (dp_info->rd_interval == 0)
-			udelay(100);
-		else
-			mdelay(dp_info->rd_interval * 4);
+		drm_dp_link_train_clock_recovery_delay(dp_info->dpcd);
 
 		if (!radeon_dp_get_link_status(dp_info->radeon_connector, dp_info->link_status)) {
 			DRM_ERROR("displayport link status failed\n");
@@ -813,10 +810,7 @@
 	dp_info->tries = 0;
 	channel_eq = false;
 	while (1) {
-		if (dp_info->rd_interval == 0)
-			udelay(400);
-		else
-			mdelay(dp_info->rd_interval * 4);
+		drm_dp_link_train_channel_eq_delay(dp_info->dpcd);
 
 		if (!radeon_dp_get_link_status(dp_info->radeon_connector, dp_info->link_status)) {
 			DRM_ERROR("displayport link status failed\n");
@@ -901,14 +895,13 @@
 	else
 		dp_info.enc_id |= ATOM_DP_CONFIG_LINK_A;
 
-	dp_info.rd_interval = radeon_read_dpcd_reg(radeon_connector, DP_TRAINING_AUX_RD_INTERVAL);
 	tmp = radeon_read_dpcd_reg(radeon_connector, DP_MAX_LANE_COUNT);
 	if (ASIC_IS_DCE5(rdev) && (tmp & DP_TPS3_SUPPORTED))
 		dp_info.tp3_supported = true;
 	else
 		dp_info.tp3_supported = false;
 
-	memcpy(dp_info.dpcd, dig_connector->dpcd, 8);
+	memcpy(dp_info.dpcd, dig_connector->dpcd, DP_RECEIVER_CAP_SIZE);
 	dp_info.rdev = rdev;
 	dp_info.encoder = encoder;
 	dp_info.connector = connector;