drm/radeon/kms: improve bpc handling (v2)

Improve handling of bpc (bits per color) in radeon.
In most cases we want 8 except for HDMI, DP, LVDS, and eDP.

v2: handle DP better.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Tested-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index b5ff1f7..2fab38f 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -588,8 +588,7 @@
 		if (encoder->crtc == crtc) {
 			radeon_encoder = to_radeon_encoder(encoder);
 			connector = radeon_get_connector_for_encoder(encoder);
-			/* if (connector && connector->display_info.bpc)
-				bpc = connector->display_info.bpc; */
+			bpc = radeon_get_monitor_bpc(connector);
 			encoder_mode = atombios_get_encoder_mode(encoder);
 			is_duallink = radeon_dig_monitor_is_duallink(encoder, mode->clock);
 			if ((radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT | ATOM_DEVICE_DFP_SUPPORT)) ||
@@ -965,9 +964,7 @@
 		struct radeon_connector_atom_dig *dig_connector =
 			radeon_connector->con_priv;
 		int dp_clock;
-
-		/* if (connector->display_info.bpc)
-			bpc = connector->display_info.bpc; */
+		bpc = radeon_get_monitor_bpc(connector);
 
 		switch (encoder_mode) {
 		case ATOM_ENCODER_MODE_DP_MST: