[06/32] drm/tegra: dp: Read fast training capability from link

Commit Message

Thierry Reding Oct. 24, 2019, 4:45 p.m. UTC

From: Thierry Reding <[e-mail]>

While probing the DisplayPort link, query the fast training capability.
If supported, drivers can use the fast link training sequence instead of
the more involved full link training sequence.

Signed-off-by: Thierry Reding <[e-mail]>
---
 drivers/gpu/drm/tegra/dp.c | 3 +++
 drivers/gpu/drm/tegra/dp.h | 7 +++++++
 2 files changed, 10 insertions(+)

Patch

diff --git a/drivers/gpu/drm/tegra/dp.c b/drivers/gpu/drm/tegra/dp.c
index f9234f66062d..97fc0225483f 100644
--- a/drivers/gpu/drm/tegra/dp.c
+++ b/drivers/gpu/drm/tegra/dp.c
@@ -11,12 +11,14 @@ 
 static void drm_dp_link_caps_reset(struct drm_dp_link_caps *caps)
 {
 	caps->enhanced_framing = false;
+	caps->fast_training = false;
 }
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
 			   const struct drm_dp_link_caps *src)
 {
 	dest->enhanced_framing = src->enhanced_framing;
+	dest->fast_training = src->fast_training;
 }
 
 static void drm_dp_link_reset(struct drm_dp_link *link)
@@ -61,6 +63,7 @@  int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	link->max_lanes = drm_dp_max_lane_count(dpcd);
 
 	link->caps.enhanced_framing = drm_dp_enhanced_frame_cap(dpcd);
+	link->caps.fast_training = drm_dp_fast_training_cap(dpcd);
 
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
diff --git a/drivers/gpu/drm/tegra/dp.h b/drivers/gpu/drm/tegra/dp.h
index 6246f9afb5fe..d6ae477bab5c 100644
--- a/drivers/gpu/drm/tegra/dp.h
+++ b/drivers/gpu/drm/tegra/dp.h
@@ -21,6 +21,13 @@  struct drm_dp_link_caps {
 	 * enhanced framing capability (mandatory as of DP 1.2)
 	 */
 	bool enhanced_framing;
+
+	/**
+	 * @fast_training:
+	 *
+	 * AUX CH handshake not required for link training
+	 */
+	bool fast_training;
 };
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,