From 8cda78b1281d59ffa3032a3885e6ffc8eb79062c Mon Sep 17 00:00:00 2001
From: Thierry Reding <treding@nvidia.com>
Date: Mon, 21 Oct 2019 16:34:27 +0200
Subject: drm/dp: Add drm_dp_fast_training_cap() helper
Git-commit: 8cda78b1281d59ffa3032a3885e6ffc8eb79062c
Patch-mainline: v5.5-rc1
References: bsc#1152472
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
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
include/drm/drm_dp_helper.h | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index e0e76f7634a9..1179d3f2ba7c 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])
{
--
2.28.0