[PATCH v3 03/13] drm/dp: Add drm_dp_fast_training_cap() helper

Thierry Reding thierry.reding at gmail.com
Mon Oct 21 14:34:27 UTC 2019


From: Thierry Reding <treding at nvidia.com>

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

Reviewed-by: Lyude Paul <lyude at redhat.com>
Signed-off-by: Thierry Reding <treding at nvidia.com>
---
 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])
 {
-- 
2.23.0



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