[PATCH v6 04/10] drm/msm/dp: Move link training to atomic_enable()

From: Dmitry Baryshkov

Date: Sun May 24 2026 - 06:36:38 EST


From: Jessica Zhang <jessica.zhang@xxxxxxxxxxxxxxxx>

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

Link disabling is already done in atomic_post_disable() (as part of the
dp_ctrl_off_link_stream() helper).

Signed-off-by: Jessica Zhang <jessica.zhang@xxxxxxxxxxxxxxxx>
Tested-by: Val Packett <val@xxxxxxxxxxxx> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@xxxxxxxxxxxxxxxx> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_display.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 97c4752005c0..036b4a5cece5 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -437,11 +437,6 @@ 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);

@@ -1699,6 +1694,13 @@ 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);
+ // TODO: schedule drm_connector_set_link_status_property()
+ return;
+ }
+
msm_dp_display_enable(msm_dp_display, force_link_train);

rc = msm_dp_display_post_enable(dp);

--
2.47.3