| Message ID | 1626191647-13901-8-git-send-email-khsieh@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | add fixes to pass DP Link Layer compliance test cases | expand |
Quoting Kuogee Hsieh (2021-07-13 08:54:07) > diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c > index 6a013b0..20951c8 100644 > --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c > +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c > @@ -1638,6 +1638,25 @@ static bool dp_ctrl_clock_recovery_any_ok( > return drm_dp_clock_recovery_ok(link_status, lane_count); > } > > +static bool dp_ctrl_loss_symbol_lock(struct dp_ctrl_private *ctrl) > +{ > + u8 link_status[DP_LINK_STATUS_SIZE]; > + u8 status; > + int i; > + int num_lanes = ctrl->link->link_params.num_lanes; > + > + dp_ctrl_read_link_status(ctrl, link_status); > + > + for (i = 0; i < num_lanes; i++) { > + status = link_status[i / 2]; > + status >>= ((i % 2) * 4); > + if (!(status & DP_LANE_SYMBOL_LOCKED)) > + return true; > + } > + > + return false; > +} Can this function move to drivers/gpu/drm/drm_dp_helper.c and be called drm_dp_symbol_locked()? > + > int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) > { > int rc = 0;
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 6a013b0..20951c8 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1638,6 +1638,25 @@ static bool dp_ctrl_clock_recovery_any_ok( return drm_dp_clock_recovery_ok(link_status, lane_count); } +static bool dp_ctrl_loss_symbol_lock(struct dp_ctrl_private *ctrl) +{ + u8 link_status[DP_LINK_STATUS_SIZE]; + u8 status; + int i; + int num_lanes = ctrl->link->link_params.num_lanes; + + dp_ctrl_read_link_status(ctrl, link_status); + + for (i = 0; i < num_lanes; i++) { + status = link_status[i / 2]; + status >>= ((i % 2) * 4); + if (!(status & DP_LANE_SYMBOL_LOCKED)) + return true; + } + + return false; +} + int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) { int rc = 0; @@ -1761,6 +1780,13 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) return rc; } +static int dp_ctrl_link_retrain(struct dp_ctrl_private *ctrl) +{ + int training_step = DP_TRAINING_NONE; + + return dp_ctrl_setup_main_link(ctrl, &training_step); +} + int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) { int ret = 0; @@ -1786,6 +1812,9 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) } } + if (dp_ctrl_loss_symbol_lock(ctrl)) + dp_ctrl_link_retrain(ctrl); + /* stop txing train pattern to end link training */ dp_ctrl_clear_training_pattern(ctrl);
Main link symbol locked is achieved at end of link training 2. Some dongle main link symbol may become unlocked again if host did not end link training soon enough after completion of link training 2. Host have to re train main link if loss of symbol lock detected before end link training so that the coming video stream can be transmitted to sink properly. Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org> --- drivers/gpu/drm/msm/dp/dp_ctrl.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)