For some DP dungles, we need to train more than onece to confirm that we
don't misjudge the status of sink device.
Signed-off-by: Bo-Chen Chen <rex-bc.chen@xxxxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_dp.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index ce817cb59445..80d7d6488105 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -42,6 +42,7 @@
#define MTK_DP_CHECK_SINK_CAP_TIMEOUT_COUNT 3
#define MTK_DP_TBC_BUF_READ_START_ADDR 0x08
#define MTK_DP_TRAIN_DOWNSCALE_RETRY 8
+#define MTK_DP_TRAIN_CLEAR_RETRY 50
struct mtk_dp_train_info {
bool tps3;
@@ -1431,11 +1432,25 @@ static int mtk_dp_video_config(struct mtk_dp *mtk_dp)
static int mtk_dp_training(struct mtk_dp *mtk_dp)
{
+ short max_retry = MTK_DP_TRAIN_CLEAR_RETRY;
int ret;
- ret = mtk_dp_train_start(mtk_dp);
- if (ret)
- return ret;
+ /*
+ * We do retry to confirm that we don't misjudge the sink status.
+ * If it is still failed, we can confirm there are some issues for the
+ * sink device.
+ */
+ do {
+ ret = mtk_dp_train_start(mtk_dp);
+ if (!ret)
+ break;
+ } while (--max_retry);
+
+ dev_info(mtk_dp->dev, "dp training clear retry times: %d\n",
+ MTK_DP_TRAIN_CLEAR_RETRY - max_retry);
+
+ if (!max_retry)
+ return -ETIMEDOUT;
ret = mtk_dp_video_config(mtk_dp);
if (ret)
--
2.18.0
