Setting the link bandwidth may change the PLL parameters, which will cause the PLL to go out of lock, so make sure to apply the MACRO_RST, which according to the comment is required to be pulsed after the PLL is locked. Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx> Reviewed-by: Robert Foss <rfoss@xxxxxxxxxx> Tested-by: Heiko Stuebner <heiko@xxxxxxxxx> (rk3288-veyron and rk3399-gru) --- .../gpu/drm/bridge/analogix/analogix_dp_core.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index bbf2c0808ace..d2c7a9117ce3 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -243,6 +243,11 @@ static int analogix_dp_link_start(struct analogix_dp_device *dp) /* Set link rate and count as you want to establish*/ analogix_dp_set_link_bandwidth(dp, dp->link_train.link_rate); + /* + * MACRO_RST must be applied after the PLL_LOCK to avoid + * the DP inter pair skew issue for at least 10 us + */ + analogix_dp_reset_macro(dp); analogix_dp_set_lane_count(dp, dp->link_train.lane_count); /* Setup RX configuration */ @@ -562,12 +567,6 @@ static int analogix_dp_full_link_train(struct analogix_dp_device *dp, int retval = 0; bool training_finished = false; - /* - * MACRO_RST must be applied after the PLL_LOCK to avoid - * the DP inter pair skew issue for at least 10 us - */ - analogix_dp_reset_macro(dp); - /* Initialize by reading RX's DPCD */ analogix_dp_get_max_rx_bandwidth(dp, &dp->link_train.link_rate); analogix_dp_get_max_rx_lane_count(dp, &dp->link_train.lane_count); @@ -634,9 +633,12 @@ static int analogix_dp_fast_link_train(struct analogix_dp_device *dp) u8 link_align, link_status[2]; enum pll_status status; - analogix_dp_reset_macro(dp); - analogix_dp_set_link_bandwidth(dp, dp->link_train.link_rate); + /* + * MACRO_RST must be applied after the PLL_LOCK to avoid + * the DP inter pair skew issue for at least 10 us + */ + analogix_dp_reset_macro(dp); analogix_dp_set_lane_count(dp, dp->link_train.lane_count); analogix_dp_set_lane_link_training(dp); -- 2.39.2
