IT6505 supports HW auto link training which will write DPCD and check
training status automatically. Some DP device can not pass
HW auto link training and must set link training step by step.
when HW auto link training fail, it may trigger video FIFO error,
and link training process will reset to beginning, and never try
step training method.
Modify training method improve compatibility to these DP devices.
v1 -> v2:
1. Split [PATCH 1/3] into 3 commits
2. Drop non necessary variable auto_ttrain_retry
v1 link:
https://lore.kernel.org/all/20250318-fix-link-training-v1-0-192667111...@ite.com.tw/
Signed-off-by: Hermes Wu <hermes...@ite.com.tw>
---
Hermes Wu (5):
drm/bridge: it6505: fix link training state HW register reset
drm/bridge: it6505: check INT_LINK_TRAIN_FAIL while link auto training
drm/bridge: it6505: modify DP link auto training
drm/bridge: it6505: modify DP link training work
drm/bridge: it6505: skip auto training when previous try fail
drivers/gpu/drm/bridge/ite-it6505.c | 112 +++++++++++++++++++++---------------
1 file changed, 65 insertions(+), 47 deletions(-)
---
base-commit: 938fbb16aba8f7b88e0fdcf56f315a5bbad41aad
change-id: 20250121-fix-link-training-461495494655
Best regards,
--
Hermes Wu <hermes...@ite.com.tw>
