[PATCH RESEND 3/3] drm/bridge: it6505: skip auto training when previous try fail

[Hermes Wu via B4 Relay]

From: Hermes Wu <hermes...@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...@ite.com.tw>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c 
b/drivers/gpu/drm/bridge/ite-it6505.c
index 
11231a642bbe185c4f36bf5f2a0b115fa056213b..730481a9446ff00a54ef70e86b4c28ff0a3f417e
 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -468,6 +468,7 @@ struct it6505 {
        struct work_struct hdcp_wait_ksv_list;
        struct completion extcon_completion;
        u8 auto_train_retry;
+       u8 step_train_only;
        bool hdcp_desired;
        bool is_repeater;
        u8 hdcp_down_stream_count;
@@ -2459,11 +2460,13 @@ 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);
 }
@@ -2479,21 +2482,23 @@ static void it6505_link_training_work(struct 
work_struct *work)
 
        if (!it6505_get_sink_hpd_status(it6505))
                return;
-
-       retry = it6505->auto_train_retry;
-       do {
-               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, auto_train_retry: %d",
-                            ret ? "pass" : "failed", it6505->auto_train_retry);
-               if (ret) {
-                       it6505_link_train_ok(it6505);
-                       return;
-               }
-       } while (retry--);
+       /* skip auto training if previous auto train is fail*/
+       if (!it6505->step_train_only) {
+               retry = it6505->auto_train_retry;
+               do {
+                       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, 
auto_train_retry: %d",
+                               ret ? "pass" : "failed", 
it6505->auto_train_retry);
+                       if (ret) {
+                               it6505_link_train_ok(it6505);
+                               return;
+                       }
+               } while (retry--);
+       }
 
        /*After HW auto training fail, try link training step by step*/
        it6505_link_step_train_process(it6505);
@@ -2605,6 +2610,7 @@ static void it6505_irq_hpd(struct it6505 *it6505)
                        it6505_parse_link_capabilities(it6505);
                }
                it6505->auto_train_retry = AUTO_TRAIN_RETRY;
+               it6505->step_train_only = false;
 
                it6505_drm_dp_link_set_power(&it6505->aux, &it6505->link,
                                             DP_SET_POWER_D0);

-- 
2.34.1