[PATCH 18/19] drm/msm/dp: Move link training to atomic_enable()

[Jessica Zhang]

Currently, the DP link training is being done during HPD. Move
link training to atomic_enable() in accordance with the atomic_enable()
documentation.

In addition, don't disable the link until atomic_post_disable() (as part
of the dp_ctrl_off[_link_stream]() helpers).

Since the link training is moved to a later part of the enable sequence,
change the bridge detect() to return true when the display is physically
connected instead of when the link is ready.

Finally, call the plug/unplug handlers directly in hpd_notify() instead
of queueing them in the event thread so that they aren't preempted by
other events.

Signed-off-by: Jessica Zhang <jessica.zhang at oss.qualcomm.com>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 15 ++++++++-------
 drivers/gpu/drm/msm/dp/dp_drm.c     |  6 +++---
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 87f2750a99ca..32e1ee40c2c3 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -410,11 +410,6 @@ static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp)
 	msm_dp_link_psm_config(dp->link, &dp->panel->link_info, false);
 
 	msm_dp_link_reset_phy_params_vx_px(dp->link);
-	rc = msm_dp_ctrl_on_link(dp->ctrl);
-	if (rc) {
-		DRM_ERROR("failed to complete DP link training\n");
-		goto end;
-	}
 
 	msm_dp_add_event(dp, EV_USER_NOTIFICATION, true, 0);
 
@@ -1561,6 +1556,12 @@ void msm_dp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
 		force_link_train = true;
 	}
 
+	rc = msm_dp_ctrl_on_link(msm_dp_display->ctrl);
+	if (rc) {
+		DRM_ERROR("Failed link training (rc=%d)\n", rc);
+		dp->connector->state->link_status = DRM_LINK_STATUS_BAD;
+	}
+
 	msm_dp_display_enable(msm_dp_display, force_link_train);
 
 	rc = msm_dp_display_post_enable(dp);
@@ -1706,7 +1707,7 @@ void msm_dp_bridge_hpd_notify(struct drm_bridge *bridge,
 		return;
 
 	if (!msm_dp_display->link_ready && status == connector_status_connected)
-		msm_dp_add_event(dp, EV_HPD_PLUG_INT, 0, 0);
+		msm_dp_hpd_plug_handle(dp, 0);
 	else if (msm_dp_display->link_ready && status == connector_status_disconnected)
-		msm_dp_add_event(dp, EV_HPD_UNPLUG_INT, 0, 0);
+		msm_dp_hpd_unplug_handle(dp, 0);
 }
diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
index b12a43499c54..3bcdf00b2d95 100644
--- a/drivers/gpu/drm/msm/dp/dp_drm.c
+++ b/drivers/gpu/drm/msm/dp/dp_drm.c
@@ -26,10 +26,10 @@ static enum drm_connector_status msm_dp_bridge_detect(struct drm_bridge *bridge)
 
 	dp = to_dp_bridge(bridge)->msm_dp_display;
 
-	drm_dbg_dp(dp->drm_dev, "link_ready = %s\n",
-		str_true_false(dp->link_ready));
+	drm_dbg_dp(dp->drm_dev, "connected = %s\n",
+		str_true_false(dp->connected));
 
-	return (dp->link_ready) ? connector_status_connected :
+	return (dp->connected) ? connector_status_connected :
 					connector_status_disconnected;
 }
 

-- 
2.50.1