[PATCH v2 5/5] drm/bridge: it6505: skip auto training when previous try fail

[Hermes Wu via B4 Relay <devnull+Hermes.wu.ite.com.tw@kernel.org>]

From: Hermes Wu <Hermes.wu@ite.com.tw>

When connect to device which can only training done by
step training, skip auto training when link training restart,
usually happen when display resolution is changed.

Signed-off-by: Hermes Wu <Hermes.wu@ite.com.tw>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 2bbe787ccb1b57906f2a31a011dd92f327019b08..47f8134df8b6f5c2172c6cfdbc91da8063993a05 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -467,6 +467,7 @@ struct it6505 {
 	struct delayed_work hdcp_work;
 	struct work_struct hdcp_wait_ksv_list;
 	struct completion extcon_completion;
+	u8 step_train_only;
 	bool hdcp_desired;
 	bool is_repeater;
 	u8 hdcp_down_stream_count;
@@ -2457,11 +2458,13 @@ static void it6505_link_step_train_process(struct it6505 *it6505)
 				     ret ? "pass" : "failed", i + 1);
 		if (ret) {
 			it6505_link_train_ok(it6505);
+			it6505->step_train_only = true;
 			return;
 		}
 	}
 
 	DRM_DEV_DEBUG_DRIVER(dev, "training fail");
+	it6505->step_train_only = false;
 	it6505->link_state = LINK_IDLE;
 	it6505_video_reset(it6505);
 }
@@ -2477,18 +2480,19 @@ static void it6505_link_training_work(struct work_struct *work)
 
 	if (!it6505_get_sink_hpd_status(it6505))
 		return;
-
-	for (retry = AUTO_TRAIN_RETRY; retry > 0; retry--) {
-		it6505_link_training_setup(it6505);
-		it6505_reset_hdcp(it6505);
-		it6505_aux_reset(it6505);
-
-		ret = it6505_link_start_auto_train(it6505);
-		DRM_DEV_DEBUG_DRIVER(dev, "auto train %s,",
-				     ret ? "pass" : "failed");
-		if (ret) {
-			it6505_link_train_ok(it6505);
-			return;
+	if (!it6505->step_train_only) {
+		for (retry = AUTO_TRAIN_RETRY; retry > 0; retry--) {
+			it6505_link_training_setup(it6505);
+			it6505_reset_hdcp(it6505);
+			it6505_aux_reset(it6505);
+
+			ret = it6505_link_start_auto_train(it6505);
+			DRM_DEV_DEBUG_DRIVER(dev, "auto train %s,",
+					     ret ? "pass" : "failed");
+			if (ret) {
+				it6505_link_train_ok(it6505);
+				return;
+			}
 		}
 	}
 
@@ -2599,6 +2603,7 @@ static void it6505_irq_hpd(struct it6505 *it6505)
 			it6505_variable_config(it6505);
 			it6505_parse_link_capabilities(it6505);
 		}
+		it6505->step_train_only = false;
 
 		it6505_drm_dp_link_set_power(&it6505->aux, &it6505->link,
 					     DP_SET_POWER_D0);

-- 
2.34.1