Re: [PATCH v1 2/2] drm/msm/dp: do not stop transmitting phy test pattern during DP phy compliance test
Quoting Kuogee Hsieh (2022-04-25 15:11:03)
> 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.
And what does the patch do to fix it? We need more details in the commit
text. I think it should continue with:
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' because XYZ and it's OK/better to retrain the link after
enabling the stream clks because XYZ.
>
> Fixes: 64e190e720a7 ("drm/msm/dp: DisplayPort PHY compliance tests fixup")
Should be
Fixes: 6625e2637d93 ("drm/msm/dp: DisplayPort PHY compliance tests fixup")
> Signed-off-by: Kuogee Hsieh
> ---
> drivers/gpu/drm/msm/dp/dp_ctrl.c | 15 +++
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index 193cc1a..f99e173 100644
> --- 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;
Why is this removed? Can you mention in the commit text why we don't
need to zero it out anymore?
>
> 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 +1831,13 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl)
> return 0;
> }
>
> + if (!dp_ctrl_channel_eq_ok(ctrl)) {
> + dp_ctrl_link_retrain(ctrl);
> + }
Braces not needed. Please remove.
> +
> + /* stop txing train pattern to end link training */
> + dp_ctrl_clear_training_pattern(ctrl);
> +
[PATCH v1 2/2] drm/msm/dp: do not stop transmitting phy test pattern during DP phy compliance test
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.
Fixes: 64e190e720a7 ("drm/msm/dp: DisplayPort PHY compliance tests fixup")
Signed-off-by: Kuogee Hsieh
---
drivers/gpu/drm/msm/dp/dp_ctrl.c | 15 +++
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 193cc1a..f99e173 100644
--- 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 +1831,13 @@ 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.
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
