On Fri, May 3, 2024 at 5:13 PM Lucas Stach <l.stach@xxxxxxxxxxxxxx> wrote: > > 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> > --- > .../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 b4a47311cfe8..736b2ed745e1 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 */ > @@ -565,12 +570,6 @@ 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); > @@ -637,9 +636,12 @@ 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 > This patch does not apply on drm-misc/drm-misc-next as far as I can tell.
