From 127c8d85cf4420167ed577121ea62f56ce13635e Mon Sep 17 00:00:00 2001 From: Alper Nebi Yasak Date: Tue, 6 Oct 2020 23:39:51 +0300 Subject: [PATCH] video: rockchip: Add missing dpcd_write() call to link_train_ce() Found this by comparing it to the coreboot driver, a form of this call was introduced there in their commit b9a7877568cf ("rockchip/*: refactor edp driver"). This is copy-pasted from U-Boot's link_train_cr() slightly above it. Without this on a gru-kevin chromebook, I have: clock recovery at voltage 0 pre-emphasis 0 requested signal parameters: lane 0 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 1 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 2 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 3 voltage 0.4V pre_emph 3.5dB using signal parameters: voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 0 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 1 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 2 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 3 voltage 0.4V pre_emph 3.5dB using signal parameters: voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 0 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 1 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 2 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 3 voltage 0.4V pre_emph 3.5dB using signal parameters: voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 0 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 1 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 2 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 3 voltage 0.4V pre_emph 3.5dB using signal parameters: voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 0 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 1 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 2 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 3 voltage 0.4V pre_emph 3.5dB using signal parameters: voltage 0.4V pre_emph 3.5dB channel eq failed, ret=-5 link train failed! rk_vop_probe() Device failed: ret=-5 With this, it looks like training succeeds: clock recovery at voltage 0 pre-emphasis 0 requested signal parameters: lane 0 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 1 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 2 voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 3 voltage 0.4V pre_emph 3.5dB using signal parameters: voltage 0.4V pre_emph 3.5dB requested signal parameters: lane 0 voltage 0.4V pre_emph 6dB requested signal parameters: lane 1 voltage 0.4V pre_emph 6dB requested signal parameters: lane 2 voltage 0.4V pre_emph 6dB requested signal parameters: lane 3 voltage 0.4V pre_emph 6dB using signal parameters: voltage 0.4V pre_emph 6dB requested signal parameters: lane 0 voltage 0.4V pre_emph 0dB requested signal parameters: lane 1 voltage 0.4V pre_emph 0dB requested signal parameters: lane 2 voltage 0.4V pre_emph 0dB requested signal parameters: lane 3 voltage 0.4V pre_emph 0dB using signal parameters: voltage 0.4V pre_emph 0dB channel eq at voltage 0 pre-emphasis 0 config video failed rk_vop_probe() Device failed: ret=-110 The "config video failed" error also goes away when I disable higher log levels, and it claims to have successfully probed the device. Signed-off-by: Alper Nebi Yasak Reviewed-by: Simon Glass Reviewed-by: Kever Yang --- drivers/video/rockchip/rk_edp.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/video/rockchip/rk_edp.c b/drivers/video/rockchip/rk_edp.c index 000bd48140..a032eb6889 100644 --- a/drivers/video/rockchip/rk_edp.c +++ b/drivers/video/rockchip/rk_edp.c @@ -559,6 +559,12 @@ static int rk_edp_link_train_ce(struct rk_edp_priv *edp) channel_eq = 0; for (tries = 0; tries < 5; tries++) { rk_edp_set_link_training(edp, edp->train_set); + ret = rk_edp_dpcd_write(regs, DPCD_TRAINING_LANE0_SET, + edp->train_set, + edp->link_train.lane_count); + if (ret) + return ret; + udelay(400); if (rk_edp_dpcd_read_link_status(edp, status) < 0) { -- 2.39.5