drm/msm/dp: do not stop transmitting phy test pattern during DP phy compliance test

[ Upstream commit 2788b4efa60c1e03ac10a156f3fdbd3be0f9198c ]

At normal operation, transmit phy test pattern has to be terminated before
DP controller switch to video ready state. However during phy compliance
testing, transmit phy test pattern should not be terminated until end of
compliance test which usually indicated by unplugged interrupt.

Only stop sending the train pattern in dp_ctrl_on_stream() if we're not
doing compliance testing. We also no longer reset 'p_level' and
'v_level' within dp_ctrl_on_link() due to both 'p_level' and 'v_level'
are acquired from link status at previous dpcd read and we like to use
those level to start link training.

Changes in v2:
-- add more details commit text
-- correct Fixes

Changes in v3:
-- drop unnecessary braces

Fixes: 2e0adc765d88 ("drm/msm/dp: do not end dp link training until video is ready")
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/483564/
Link: https://lore.kernel.org/r/1650995939-28467-3-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 193cc1a597ff21cae9d2f6e863bd41302b06adb4..08cc48af03b7d2fdf56f6b22c09fd42290e81c61 100644 (file)
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1699,8 +1699,6 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
                ctrl->link->link_params.rate,
                ctrl->link->link_params.num_lanes, ctrl->dp_ctrl.pixel_rate);
 
-       ctrl->link->phy_params.p_level = 0;
-       ctrl->link->phy_params.v_level = 0;
 
        rc = dp_ctrl_enable_mainlink_clocks(ctrl);
        if (rc)
@@ -1822,12 +1820,6 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl)
                }
        }
 
-       if (!dp_ctrl_channel_eq_ok(ctrl))
-               dp_ctrl_link_retrain(ctrl);
-
-       /* stop txing train pattern to end link training */
-       dp_ctrl_clear_training_pattern(ctrl);
-
        ret = dp_ctrl_enable_stream_clocks(ctrl);
        if (ret) {
                DRM_ERROR("Failed to start pixel clocks. ret=%d\n", ret);
@@ -1839,6 +1831,12 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl)
                return 0;
        }
 
+       if (!dp_ctrl_channel_eq_ok(ctrl))
+               dp_ctrl_link_retrain(ctrl);
+
+       /* stop txing train pattern to end link training */
+       dp_ctrl_clear_training_pattern(ctrl);
+
        /*
         * Set up transfer unit values and set controller state to send
         * video.