From: Kuogee Hsieh <khsieh@codeaurora.org> To: dri-devel@lists.freedesktop.org, robdclark@gmail.com, sean@poorly.run, swboyd@chromium.org Cc: Kuogee Hsieh <khsieh@codeaurora.org>, abhinavk@codeaurora.org, aravindh@codeaurora.org, airlied@linux.ie, daniel@ffwll.ch, bjorn.andersson@linaro.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH 7/7] drm/msm/dp: retrain link when loss of symbol lock detected Date: Tue, 6 Jul 2021 10:20:20 -0700 [thread overview] Message-ID: <1625592020-22658-8-git-send-email-khsieh@codeaurora.org> (raw) In-Reply-To: <1625592020-22658-1-git-send-email-khsieh@codeaurora.org> 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 | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 0cb01a9..e616ab2 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1661,6 +1661,25 @@ static bool dp_ctrl_any_lane_cr_lose(struct dp_ctrl_private *ctrl, return false; } +static bool dp_ctrl_loss_symbol_lock(struct dp_ctrl_private *ctrl) +{ + u8 link_status[6]; + u8 status; + int i; + int lane = ctrl->link->link_params.num_lanes; + + dp_ctrl_read_link_status(ctrl, link_status); + + for (i = 0; i < lane; 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; @@ -1777,6 +1796,17 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) return rc; } +static int dp_ctrl_link_retrain(struct dp_ctrl_private *ctrl) +{ + int ret = 0; + u8 cr_status[2]; + int training_step = DP_TRAINING_NONE; + + ret = dp_ctrl_setup_main_link(ctrl, cr_status, &training_step); + + return ret; +} + int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) { int ret = 0; @@ -1802,6 +1832,10 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) } } + /* if loss symbol lock happen, then retaining the link */ + 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); -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
WARNING: multiple messages have this Message-ID (diff)
From: Kuogee Hsieh <khsieh@codeaurora.org> To: dri-devel@lists.freedesktop.org, robdclark@gmail.com, sean@poorly.run, swboyd@chromium.org Cc: airlied@linux.ie, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, abhinavk@codeaurora.org, bjorn.andersson@linaro.org, Kuogee Hsieh <khsieh@codeaurora.org>, aravindh@codeaurora.org, freedreno@lists.freedesktop.org Subject: [PATCH 7/7] drm/msm/dp: retrain link when loss of symbol lock detected Date: Tue, 6 Jul 2021 10:20:20 -0700 [thread overview] Message-ID: <1625592020-22658-8-git-send-email-khsieh@codeaurora.org> (raw) In-Reply-To: <1625592020-22658-1-git-send-email-khsieh@codeaurora.org> 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 | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 0cb01a9..e616ab2 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1661,6 +1661,25 @@ static bool dp_ctrl_any_lane_cr_lose(struct dp_ctrl_private *ctrl, return false; } +static bool dp_ctrl_loss_symbol_lock(struct dp_ctrl_private *ctrl) +{ + u8 link_status[6]; + u8 status; + int i; + int lane = ctrl->link->link_params.num_lanes; + + dp_ctrl_read_link_status(ctrl, link_status); + + for (i = 0; i < lane; 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; @@ -1777,6 +1796,17 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) return rc; } +static int dp_ctrl_link_retrain(struct dp_ctrl_private *ctrl) +{ + int ret = 0; + u8 cr_status[2]; + int training_step = DP_TRAINING_NONE; + + ret = dp_ctrl_setup_main_link(ctrl, cr_status, &training_step); + + return ret; +} + int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) { int ret = 0; @@ -1802,6 +1832,10 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl) } } + /* if loss symbol lock happen, then retaining the link */ + 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); -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2021-07-06 17:21 UTC|newest] Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-06 17:20 [PATCH 0/7] add fixes to pass DP Link Layer compliance test cases Kuogee Hsieh 2021-07-06 17:20 ` Kuogee Hsieh 2021-07-06 17:20 ` [PATCH 1/7] drm/msm/dp: use dp_ctrl_off_link_stream during PHY compliance test run Kuogee Hsieh 2021-07-06 17:20 ` Kuogee Hsieh 2021-07-08 7:03 ` Stephen Boyd 2021-07-08 7:03 ` Stephen Boyd 2021-07-08 21:33 ` khsieh 2021-07-08 21:33 ` khsieh 2021-07-06 17:20 ` [PATCH 2/7] drm/msm/dp: reduce link rate if failed at link training 1 Kuogee Hsieh 2021-07-06 17:20 ` Kuogee Hsieh 2021-07-08 7:33 ` Stephen Boyd 2021-07-08 7:33 ` Stephen Boyd 2021-07-09 17:46 ` khsieh 2021-07-09 17:46 ` khsieh 2021-07-15 18:59 ` Stephen Boyd 2021-07-15 18:59 ` Stephen Boyd 2021-07-06 17:20 ` [PATCH 3/7] drm/msm/dp: reset aux controller after dp_aux_cmd_fifo_tx() failed Kuogee Hsieh 2021-07-06 17:20 ` Kuogee Hsieh 2021-07-08 7:34 ` Stephen Boyd 2021-07-08 7:34 ` Stephen Boyd 2021-07-08 21:59 ` khsieh 2021-07-08 21:59 ` khsieh 2021-07-06 17:20 ` [PATCH 4/7] drm/msm/dp: replug event is converted into an unplug followed by an plug events Kuogee Hsieh 2021-07-06 17:20 ` Kuogee Hsieh 2021-07-08 20:56 ` Stephen Boyd 2021-07-08 20:56 ` Stephen Boyd 2021-07-06 17:20 ` [PATCH 5/7] drm/msm/dp: return correct edid checksum after corrupted edid checksum read Kuogee Hsieh 2021-07-06 17:20 ` Kuogee Hsieh 2021-07-08 7:14 ` Stephen Boyd 2021-07-08 7:14 ` Stephen Boyd 2021-07-09 18:16 ` khsieh 2021-07-09 18:16 ` khsieh 2021-07-06 17:20 ` [PATCH 6/7] drm/msm/dp: do not end dp link training until video is ready Kuogee Hsieh 2021-07-06 17:20 ` Kuogee Hsieh 2021-07-06 17:20 ` Kuogee Hsieh [this message] 2021-07-06 17:20 ` [PATCH 7/7] drm/msm/dp: retrain link when loss of symbol lock detected Kuogee Hsieh 2021-07-08 7:21 ` Stephen Boyd 2021-07-08 7:21 ` Stephen Boyd 2021-07-09 17:16 ` khsieh 2021-07-09 17:16 ` khsieh 2021-07-15 19:00 ` Stephen Boyd 2021-07-15 19:00 ` Stephen Boyd
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