Messages in this thread | | | Date | Mon, 1 Aug 2022 13:18:35 -0700 | Subject | Re: [Freedreno] [PATCH v2] drm/msm/dp: delete DP_RECOVERED_CLOCK_OUT_EN to fix tps4 | From | Abhinav Kumar <> |
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On 8/1/2022 1:13 PM, Kuogee Hsieh wrote: > Data Symbols scrambled is required for tps4 at link training 2. > Therefore SCRAMBLING_DISABLE bit should not be set for tps4 to > work. > RECOVERED_CLOCK_OUT_EN is for enable simple EYE test for jitter > measurement with minimal equipment for embedded applications purpose > and is not required to be set during normal operation. > Current implementation always have RECOVERED_CLOCK_OUT_EN bit set > which cause SCRAMBLING_DISABLE bit wrongly set at tps4 which prevent > tps4 from working. > This patch delete setting RECOVERED_CLOCK_OUT_EN to fix SCRAMBLING_DISABLE > be wrongly set at tps4. > > Changes in v2: > -- fix Fixes tag > > Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support") > Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
This is a good catch !
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> --- > drivers/gpu/drm/msm/dp/dp_ctrl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c > index ab6aa13..013ca02 100644 > --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c > +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c > @@ -1214,7 +1214,7 @@ static int dp_ctrl_link_train_2(struct dp_ctrl_private *ctrl, > if (ret) > return ret; > > - dp_ctrl_train_pattern_set(ctrl, pattern | DP_RECOVERED_CLOCK_OUT_EN); > + dp_ctrl_train_pattern_set(ctrl, pattern); > > for (tries = 0; tries <= maximum_retries; tries++) { > drm_dp_link_train_channel_eq_delay(ctrl->aux, ctrl->panel->dpcd);
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