Re: [PATCH v2 03/38] drm/msm/dp: break up dp_display_enable into two parts

[Yongxing Mou <quic_yongmou@quicinc.com>]

On 2025/6/9 20:59, Dmitry Baryshkov wrote:
> On Mon, Jun 09, 2025 at 08:21:22PM +0800, Yongxing Mou wrote:
>> From: Abhinav Kumar <quic_abhinavk@quicinc.com>
>>
>> dp_display_enable() currently re-trains the link if needed
>> and then enables the pixel clock, programs the controller to
>> start sending the pixel stream. Splite these two parts into
>> prepare/enable APIs, to support MST bridges_enable inserte
> 
> typos
> 
..Got it. thanks.
>> the MST payloads funcs between enable stream_clks and programe
>> register.
>>
>> Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
>> Signed-off-by: Yongxing Mou <quic_yongmou@quicinc.com>
>> ---
>>   drivers/gpu/drm/msm/dp/dp_ctrl.c    | 57 +++++++++++++--------
>>   drivers/gpu/drm/msm/dp/dp_ctrl.h    |  3 +-
>>   drivers/gpu/drm/msm/dp/dp_display.c | 99 +++++++++++++++++++++++++++----------
>>   drivers/gpu/drm/msm/dp/dp_display.h |  1 +
>>   4 files changed, 111 insertions(+), 49 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
>> index a50bfafbb4ea85c114c958ea0ed24362a1f23136..1e13ca81b0155a37a4ed7a2e83c918293d703a37 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
>> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
>> @@ -1980,40 +1980,61 @@ static int msm_dp_ctrl_link_retrain(struct msm_dp_ctrl_private *ctrl)
>>   	return msm_dp_ctrl_setup_main_link(ctrl, &training_step);
>>   }
>>   
>> -int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, bool force_link_train)
>> +int msm_dp_ctrl_prepare_stream_on(struct msm_dp_ctrl *msm_dp_ctrl, bool force_link_train)
>>   {
>>   	int ret = 0;
>> -	bool mainlink_ready = false;
>>   	struct msm_dp_ctrl_private *ctrl;
>> -	unsigned long pixel_rate;
>> -	unsigned long pixel_rate_orig;
>>   
>>   	if (!msm_dp_ctrl)
>>   		return -EINVAL;
>>   
>>   	ctrl = container_of(msm_dp_ctrl, struct msm_dp_ctrl_private, msm_dp_ctrl);
>>   
>> -	pixel_rate = pixel_rate_orig = ctrl->panel->msm_dp_mode.drm_mode.clock;
>> -
>> -	if (msm_dp_ctrl->wide_bus_en || ctrl->panel->msm_dp_mode.out_fmt_is_yuv_420)
>> -		pixel_rate >>= 1;
>> -
>> -	drm_dbg_dp(ctrl->drm_dev, "rate=%d, num_lanes=%d, pixel_rate=%lu\n",
>> -		ctrl->link->link_params.rate,
>> -		ctrl->link->link_params.num_lanes, pixel_rate);
>> +	drm_dbg_dp(ctrl->drm_dev, "rate=%d, num_lanes=%d\n",
>> +		   ctrl->link->link_params.rate,
>> +		   ctrl->link->link_params.num_lanes);
> 
> Please don't mix whitespace changes with the actual code changes. It
> makes reviewing the patch much harder.
> 
Okay.
>>   
>>   	drm_dbg_dp(ctrl->drm_dev,
>> -		"core_clk_on=%d link_clk_on=%d stream_clk_on=%d\n",
>> -		ctrl->core_clks_on, ctrl->link_clks_on, ctrl->stream_clks_on);
>> +		   "core_clk_on=%d link_clk_on=%d stream_clk_on=%d\n",
>> +		   ctrl->core_clks_on, ctrl->link_clks_on, ctrl->stream_clks_on);
>>   
>>   	if (!ctrl->link_clks_on) { /* link clk is off */
>>   		ret = msm_dp_ctrl_enable_mainlink_clocks(ctrl);
>>   		if (ret) {
>>   			DRM_ERROR("Failed to start link clocks. ret=%d\n", ret);
>> -			goto end;
>> +			return ret;
>>   		}
>>   	}
>>   
>> +	if (force_link_train || !msm_dp_ctrl_channel_eq_ok(ctrl))
>> +		msm_dp_ctrl_link_retrain(ctrl);
>> +
>> +	/* stop txing train pattern to end link training */
>> +	msm_dp_ctrl_clear_training_pattern(ctrl, DP_PHY_DPRX);
>> +
>> +	return ret;
>> +}
>> +
>> +int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl)
>> +{
>> +	int ret = 0;
>> +	bool mainlink_ready = false;
>> +	struct msm_dp_ctrl_private *ctrl;
>> +	unsigned long pixel_rate;
>> +	unsigned long pixel_rate_orig;
>> +
>> +	if (!msm_dp_ctrl)
>> +		return -EINVAL;
>> +
>> +	ctrl = container_of(msm_dp_ctrl, struct msm_dp_ctrl_private, msm_dp_ctrl);
>> +
>> +	pixel_rate = pixel_rate_orig = ctrl->panel->msm_dp_mode.drm_mode.clock;
>> +
>> +	if (msm_dp_ctrl->wide_bus_en || ctrl->panel->msm_dp_mode.out_fmt_is_yuv_420)
>> +		pixel_rate >>= 1;
>> +
>> +	drm_dbg_dp(ctrl->drm_dev, "pixel_rate=%lu\n", pixel_rate);
>> +
>>   	ret = clk_set_rate(ctrl->pixel_clk, pixel_rate * 1000);
>>   	if (ret) {
>>   		DRM_ERROR("Failed to set pixel clock rate. ret=%d\n", ret);
>> @@ -2031,12 +2052,6 @@ int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, bool force_link_train
>>   		ctrl->stream_clks_on = true;
>>   	}
>>   
>> -	if (force_link_train || !msm_dp_ctrl_channel_eq_ok(ctrl))
>> -		msm_dp_ctrl_link_retrain(ctrl);
>> -
>> -	/* stop txing train pattern to end link training */
>> -	msm_dp_ctrl_clear_training_pattern(ctrl, DP_PHY_DPRX);
>> -
>>   	/*
>>   	 * Set up transfer unit values and set controller state to send
>>   	 * video.
>> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.h b/drivers/gpu/drm/msm/dp/dp_ctrl.h
>> index b7abfedbf5749c25877a0b8ba3af3d8ed4b23d67..42745c912adbad7221c78f5cecefa730bfda1e75 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.h
>> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.h
>> @@ -18,7 +18,8 @@ struct msm_dp_ctrl {
>>   struct phy;
>>   
>>   int msm_dp_ctrl_on_link(struct msm_dp_ctrl *msm_dp_ctrl);
>> -int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, bool force_link_train);
>> +int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl);
>> +int msm_dp_ctrl_prepare_stream_on(struct msm_dp_ctrl *dp_ctrl, bool force_link_train);
>>   void msm_dp_ctrl_off_link_stream(struct msm_dp_ctrl *msm_dp_ctrl);
>>   void msm_dp_ctrl_off_link(struct msm_dp_ctrl *msm_dp_ctrl);
>>   void msm_dp_ctrl_off(struct msm_dp_ctrl *msm_dp_ctrl);
>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
>> index 9d2db9cbd2552470a36a63f70f517c35436f7280..5ac5dcf35b789f2bda052a2c17aae20aa48d8e18 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
>> @@ -831,7 +831,37 @@ static int msm_dp_display_set_mode(struct msm_dp *msm_dp_display,
>>   	return 0;
>>   }
>>   
>> -static int msm_dp_display_enable(struct msm_dp_display_private *dp, bool force_link_train)
>> +static int msm_dp_display_prepare(struct msm_dp_display_private *dp)
>> +{
>> +	int rc = 0;
>> +	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
>> +	bool force_link_train = false;
>> +
>> +	drm_dbg_dp(dp->drm_dev, "sink_count=%d\n", dp->link->sink_count);
>> +	if (msm_dp_display->prepared) {
>> +		drm_dbg_dp(dp->drm_dev, "Link already setup, return\n");
>> +		return 0;
>> +	}
> 
> How can it be prepared here? It is called at the beginning of the
> .atomic_enable() only, so there is no way this can be true.
> 
Thanks. will update it..
>> +
>> +	rc = pm_runtime_resume_and_get(&msm_dp_display->pdev->dev);
>> +	if (rc) {
>> +		DRM_ERROR("failed to pm_runtime_resume\n");
>> +		return rc;
>> +	}
>> +
>> +	if (dp->hpd_state == ST_CONNECTED && !msm_dp_display->power_on) {
>> +		msm_dp_display_host_phy_init(dp);
>> +		force_link_train = true;
>> +	}
>> +
>> +	rc = msm_dp_ctrl_prepare_stream_on(dp->ctrl, force_link_train);
>> +	if (!rc)
>> +		msm_dp_display->prepared = true;
>> +
>> +	return rc;
>> +}
>> +
>> +static int msm_dp_display_enable(struct msm_dp_display_private *dp)
>>   {
>>   	int rc = 0;
>>   	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
>> @@ -842,7 +872,7 @@ static int msm_dp_display_enable(struct msm_dp_display_private *dp, bool force_l
>>   		return 0;
>>   	}
>>   
>> -	rc = msm_dp_ctrl_on_stream(dp->ctrl, force_link_train);
>> +	rc = msm_dp_ctrl_on_stream(dp->ctrl);
>>   	if (!rc)
>>   		msm_dp_display->power_on = true;
>>   
>> @@ -872,13 +902,10 @@ static int msm_dp_display_post_enable(struct msm_dp *msm_dp_display)
>>   	return 0;
>>   }
>>   
>> -static int msm_dp_display_disable(struct msm_dp_display_private *dp)
>> +static void msm_dp_display_audio_notify_disable(struct msm_dp_display_private *dp)
>>   {
>>   	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
>>   
>> -	if (!msm_dp_display->power_on)
>> -		return 0;
>> -
>>   	/* wait only if audio was enabled */
>>   	if (msm_dp_display->audio_enabled) {
>>   		/* signal the disconnect event */
>> @@ -889,6 +916,14 @@ static int msm_dp_display_disable(struct msm_dp_display_private *dp)
>>   	}
>>   
>>   	msm_dp_display->audio_enabled = false;
>> +}
>> +
>> +static int msm_dp_display_disable(struct msm_dp_display_private *dp)
>> +{
>> +	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
>> +
>> +	if (!msm_dp_display->power_on)
>> +		return 0;
>>   
>>   	if (dp->link->sink_count == 0) {
>>   		/*
>> @@ -1506,9 +1541,8 @@ void msm_dp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
>>   	struct msm_dp_bridge *msm_dp_bridge = to_dp_bridge(drm_bridge);
>>   	struct msm_dp *dp = msm_dp_bridge->msm_dp_display;
>>   	int rc = 0;
>> +
>>   	struct msm_dp_display_private *msm_dp_display;
>> -	u32 hpd_state;
>> -	bool force_link_train = false;
>>   
>>   	msm_dp_display = container_of(dp, struct msm_dp_display_private, msm_dp_display);
>>   
>> @@ -1516,29 +1550,23 @@ void msm_dp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
>>   		msm_dp_hpd_plug_handle(msm_dp_display, 0);
>>   
>>   	mutex_lock(&msm_dp_display->event_mutex);
>> -	if (pm_runtime_resume_and_get(&dp->pdev->dev)) {
>> -		DRM_ERROR("failed to pm_runtime_resume\n");
>> -		mutex_unlock(&msm_dp_display->event_mutex);
>> -		return;
>> -	}
>>   
>> -	hpd_state = msm_dp_display->hpd_state;
>> -	if (hpd_state == ST_DISCONNECT_PENDING) {
>> +	rc = msm_dp_display_prepare(msm_dp_display);
>> +	if (rc) {
>> +		DRM_ERROR("DP display prepare failed, rc=%d\n", rc);
>>   		mutex_unlock(&msm_dp_display->event_mutex);
>>   		return;
>>   	}
>>   
>> -	if (hpd_state == ST_CONNECTED && !dp->power_on) {
>> -		msm_dp_display_host_phy_init(msm_dp_display);
>> -		force_link_train = true;
>> -	}
>> -
>> -	msm_dp_display_enable(msm_dp_display, force_link_train);
>> -
>> -	rc = msm_dp_display_post_enable(dp);
>> -	if (rc) {
>> -		DRM_ERROR("DP display post enable failed, rc=%d\n", rc);
>> -		msm_dp_display_disable(msm_dp_display);
>> +	if (dp->prepared) {
>> +		rc = msm_dp_display_enable(msm_dp_display);
>> +		if (rc)
>> +			DRM_ERROR("DP display enable failed, rc=%d\n", rc);
>> +		rc = msm_dp_display_post_enable(dp);
>> +		if (rc) {
>> +			DRM_ERROR("DP display post enable failed, rc=%d\n", rc);
>> +			msm_dp_display_disable(msm_dp_display);
>> +		}
>>   	}
>>   
>>   	/* completed connection */
>> @@ -1560,6 +1588,20 @@ void msm_dp_bridge_atomic_disable(struct drm_bridge *drm_bridge,
>>   	msm_dp_ctrl_push_idle(msm_dp_display->ctrl);
>>   }
>>   
>> +static void msm_dp_display_unprepare(struct msm_dp_display_private *dp)
>> +{
>> +	struct msm_dp *msm_dp_display = &dp->msm_dp_display;
>> +
>> +	if (!msm_dp_display->prepared) {
>> +		drm_dbg_dp(dp->drm_dev, "Link already setup, return\n");
>> +		return;
>> +	}
> 
> Why/ how is it possible?
> 
will check it.
>> +
>> +	pm_runtime_put_sync(&msm_dp_display->pdev->dev);
>> +
>> +	msm_dp_display->prepared = false;
>> +}
>> +
>>   void msm_dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
>>   				       struct drm_atomic_state *state)
>>   {
>> @@ -1580,6 +1622,8 @@ void msm_dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
>>   		drm_dbg_dp(dp->drm_dev, "type=%d wrong hpd_state=%d\n",
>>   			   dp->connector_type, hpd_state);
>>   
>> +	msm_dp_display_audio_notify_disable(msm_dp_display);
>> +
>>   	msm_dp_display_disable(msm_dp_display);
>>   
>>   	hpd_state =  msm_dp_display->hpd_state;
>> @@ -1588,9 +1632,10 @@ void msm_dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
>>   		msm_dp_display->hpd_state = ST_DISCONNECTED;
>>   	}
>>   
>> +	msm_dp_display_unprepare(msm_dp_display);
>> +
>>   	drm_dbg_dp(dp->drm_dev, "type=%d Done\n", dp->connector_type);
>>   
>> -	pm_runtime_put_sync(&dp->pdev->dev);
>>   	mutex_unlock(&msm_dp_display->event_mutex);
>>   }
>>   
>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
>> index cc6e2cab36e9c0b1527ff292e547cbb4d69fd95c..2394840e9f28e136705004c3e6af93fbe13c33c5 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_display.h
>> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
>> @@ -19,6 +19,7 @@ struct msm_dp {
>>   	bool link_ready;
>>   	bool audio_enabled;
>>   	bool power_on;
>> +	bool prepared;
>>   	unsigned int connector_type;
>>   	bool is_edp;
>>   	bool internal_hpd;
>>
>> -- 
>> 2.34.1
>>
>