[v3,4/5] drm/bridge: it6505: modify DP link training work

Commit Message

Hermes Wu April 1, 2025, 7:54 a.m. UTC

From: Hermes Wu <[e-mail]>

The DP link training work include auto training and after
auto training failed "AUTO_TRAIN_RETRY" times, it switch to
step training mode.

It will more efficiency that finish link auto training,
include retry, and step training in a work, rather than
re-schedule train work when each training fail.

Drop auto_train_retry from it6505 structure,
and it6505_dump() is remove from link trainig work,
it takes too much time to read all register area,
and is not necessary.

Signed-off-by: Hermes Wu <[e-mail]>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 40 ++++++++++++++-----------------------
 1 file changed, 15 insertions(+), 25 deletions(-)

Patch

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index f9b99c70789eea6beb3c6513155c9a4ca103d219..bff5f18fb5ae7192242308f034b60af9807c192c 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -467,7 +467,6 @@  struct it6505 {
 	struct delayed_work hdcp_work;
 	struct work_struct hdcp_wait_ksv_list;
 	struct completion extcon_completion;
-	u8 auto_train_retry;
 	bool hdcp_desired;
 	bool is_repeater;
 	u8 hdcp_down_stream_count;
@@ -666,7 +665,7 @@  static int it6505_get_dpcd(struct it6505 *it6505, int offset, u8 *dpcd, int num)
 	return 0;
 }
 
-static void it6505_dump(struct it6505 *it6505)
+static void __maybe_unused it6505_dump(struct it6505 *it6505)
 {
 	unsigned int i, j;
 	u8 regs[16];
@@ -1399,7 +1398,6 @@  static void it6505_variable_config(struct it6505 *it6505)
 	it6505->lane_count = MAX_LANE_COUNT;
 	it6505->link_state = LINK_IDLE;
 	it6505->hdcp_desired = HDCP_DESIRED;
-	it6505->auto_train_retry = AUTO_TRAIN_RETRY;
 	it6505->audio.select = AUDIO_SELECT;
 	it6505->audio.sample_rate = AUDIO_SAMPLE_RATE;
 	it6505->audio.channel_count = AUDIO_CHANNEL_COUNT;
@@ -2467,7 +2465,7 @@  static void it6505_link_training_work(struct work_struct *work)
 {
 	struct it6505 *it6505 = container_of(work, struct it6505, link_works);
 	struct device *dev = it6505->dev;
-	int ret;
+	int ret, retry;
 
 	DRM_DEV_DEBUG_DRIVER(dev, "it6505->sink_count: %d",
 			     it6505->sink_count);
@@ -2475,27 +2473,22 @@  static void it6505_link_training_work(struct work_struct *work)
 	if (!it6505_get_sink_hpd_status(it6505))
 		return;
 
-	it6505_link_training_setup(it6505);
-	it6505_reset_hdcp(it6505);
-	it6505_aux_reset(it6505);
-
-	if (it6505->auto_train_retry < 1) {
-		it6505_link_step_train_process(it6505);
-		return;
-	}
-
-	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);
+	for (retry = AUTO_TRAIN_RETRY; retry > 0; retry--) {
+		it6505_link_training_setup(it6505);
+		it6505_reset_hdcp(it6505);
+		it6505_aux_reset(it6505);
 
-	if (ret) {
-		it6505->auto_train_retry = AUTO_TRAIN_RETRY;
-		it6505_link_train_ok(it6505);
-	} else {
-		it6505->auto_train_retry--;
-		it6505_dump(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;
+		}
 	}
 
+	/*After HW auto training fail, try link training step by step*/
+	it6505_link_step_train_process(it6505);
 }
 
 static void it6505_plugged_status_to_codec(struct it6505 *it6505)
@@ -2576,7 +2569,6 @@  static int it6505_process_hpd_irq(struct it6505 *it6505)
 			     (int)ARRAY_SIZE(link_status), link_status);
 
 	if (!drm_dp_channel_eq_ok(link_status, it6505->lane_count)) {
-		it6505->auto_train_retry = AUTO_TRAIN_RETRY;
 		it6505_video_reset(it6505);
 	}
 
@@ -2602,7 +2594,6 @@  static void it6505_irq_hpd(struct it6505 *it6505)
 			it6505_variable_config(it6505);
 			it6505_parse_link_capabilities(it6505);
 		}
-		it6505->auto_train_retry = AUTO_TRAIN_RETRY;
 
 		it6505_drm_dp_link_set_power(&it6505->aux, &it6505->link,
 					     DP_SET_POWER_D0);
@@ -2739,7 +2730,6 @@  static void it6505_irq_video_handler(struct it6505 *it6505, const int *int_statu
 			     (unsigned int *)int_status)) ||
 	    (it6505_test_bit(BIT_INT_VID_FIFO_ERROR,
 			     (unsigned int *)int_status))) {
-		it6505->auto_train_retry = AUTO_TRAIN_RETRY;
 		flush_work(&it6505->link_works);
 		it6505_stop_hdcp(it6505);
 		it6505_video_reset(it6505);