6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: xiazhengqiao <xiazhengqiao@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> [ Upstream commit ca077ff8cac5af8a5a3c476983a6dd54aa3511b7 ] To have better compatibility for DP sink, there is a retry mechanism for the link training process to switch between different training process. The original driver code doesn't reset the retry counter when training state is pass. If the system triggers link training over 3 times, there will be a chance to causes the driver to use the wrong training method and return a training fail result. To Fix this, we reset the retry counter when training state is pass each time. Signed-off-by: Allen Chen <allen.chen@xxxxxxxxxxxxxxxxxxxxxxxxxxx> Signed-off-by: xiazhengqiao <xiazhengqiao@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> Reviewed-by: Robert Foss <rfoss@xxxxxxxxxx> Signed-off-by: Robert Foss <rfoss@xxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20231221093057.7073-1-xiazhengqiao@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Stable-dep-of: 484436ec5c2b ("drm/bridge: it6505: fix hibernate to resume no display issue") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/bridge/ite-it6505.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c index 2f300f5ca051c..b589136ca6da9 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -2240,11 +2240,13 @@ static void it6505_link_training_work(struct work_struct *work) ret = it6505_link_start_auto_train(it6505); DRM_DEV_DEBUG_DRIVER(dev, "auto train %s, auto_train_retry: %d", ret ? "pass" : "failed", it6505->auto_train_retry); - it6505->auto_train_retry--; if (ret) { + it6505->auto_train_retry = AUTO_TRAIN_RETRY; it6505_link_train_ok(it6505); return; + } else { + it6505->auto_train_retry--; } it6505_dump(it6505); -- 2.43.0
