[PATCH] drm/msm/dp: don't report link training success after a reinit

[Oleg Keri <okerixx@gmail.com>]

When every training attempt fails, the retry loop in
msm_dp_ctrl_on_link() ends on a successful
msm_dp_ctrl_reinitialize_mainlink(), leaving rc at 0. The caller then
enables the stream on an untrained link and the display stays dark.

The retry counter only reaches zero in that case, so treat it as a
training failure.

Fixes: 8ede2ecc3e5e ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets")
Signed-off-by: Oleg Keri <okerixx@gmail.com>
---
 drivers/gpu/drm/msm/dp/dp_ctrl.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -2434,6 +2434,9 @@ int msm_dp_ctrl_on_link(struct msm_dp_ctrl *msm_dp_ctrl,
 	if (ctrl->link->sink_request & DP_TEST_LINK_PHY_TEST_PATTERN)
 		return rc;
 
+	if (!link_train_max_retries)
+		rc = -ETIMEDOUT;
+
 	if (rc == 0) {  /* link train successfully */
 		/*
 		 * do not stop train pattern here

base-commit: 4c253ac4b29b8c6cc6fdef8f92d4facde62e63b9
-- 
2.55.0