From: Thierry Reding <treding@nvidia.com>
Date: Mon, 21 Oct 2019 14:34:27 +0000 (+0200)
Subject: drm/dp: Add drm_dp_fast_training_cap() helper
X-Git-Tag: v5.5-rc1~128^2~24^2~10
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8cda78b1281d59ffa3032a3885e6ffc8eb79062c;p=thirdparty%2Flinux.git

drm/dp: Add drm_dp_fast_training_cap() helper

Add a helper that checks for the fast training capability given the DPCD
receiver capabilities blob.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191021143437.1477719-4-thierry.reding@gmail.com
---

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index e0e76f7634a94..1179d3f2ba7c1 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1215,6 +1215,13 @@ drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 		(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
 }
 
+static inline bool
+drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_DPCD_REV] >= 0x11 &&
+		(dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
+}
+
 static inline bool
 drm_dp_tps3_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 {