From b99ab590a5ace2e0da01e38ef9c9134216c19cfb Mon Sep 17 00:00:00 2001 From: Kuogee Hsieh Date: Thu, 11 Aug 2022 15:57:50 -0700 Subject: [PATCH] drm/msm/dp: delete DP_RECOVERED_CLOCK_OUT_EN to fix tps4 [ Upstream commit 032d57960176ac01cc5adff5bcc5eb51317f8781 ] 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 Changes in v3: -- revise commit text Changes in v4: -- fix commit text newline Changes in v5: -- fix commit text line over 75 chars Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support") Signed-off-by: Kuogee Hsieh Reviewed-by: Abhinav Kumar Reviewed-by: Stephen Boyd Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/497194/ Link: https://lore.kernel.org/r/1660258670-4200-1-git-send-email-quic_khsieh@quicinc.com Signed-off-by: Abhinav Kumar Signed-off-by: Sasha Levin --- 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 703249384e7c..45aa06a31a9f 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);