linux-kernel - Re: [PATCH 34/45] drm/msm/dp: add support to re-use and clear the panel edid

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Message-ID: <va2hxznd76lu7fei4gspvxh4usfd3ebwawd2isvbhjbxjvlldc@gd2drcvx7ts2>
Date: Sun, 8 Dec 2024 10:53:21 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Abhinav Kumar <quic_abhinavk@...cinc.com>
Cc: Rob Clark <robdclark@...il.com>, Sean Paul <sean@...rly.run>, 
	Marijn Suijten <marijn.suijten@...ainline.org>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>, Stephen Boyd <swboyd@...omium.org>, 
	Chandan Uddaraju <chandanu@...eaurora.org>, Guenter Roeck <groeck@...omium.org>, 
	Kuogee Hsieh <quic_khsieh@...cinc.com>, Bjorn Andersson <andersson@...nel.org>, 
	Konrad Dybcio <konradybcio@...nel.org>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Vara Reddy <quic_varar@...cinc.com>, Rob Clark <robdclark@...omium.org>, 
	Tanmay Shah <tanmay@...eaurora.org>, linux-arm-msm@...r.kernel.org, dri-devel@...ts.freedesktop.org, 
	freedreno@...ts.freedesktop.org, linux-kernel@...r.kernel.org, devicetree@...r.kernel.org, 
	Jessica Zhang <quic_jesszhan@...cinc.com>, Laurent Pinchart <laurent.pinchart@...asonboard.com>
Subject: Re: [PATCH 34/45] drm/msm/dp: add support to re-use and clear the
 panel edid

On Thu, Dec 05, 2024 at 08:32:05PM -0800, Abhinav Kumar wrote:
> During certain cases, the dp mst connector's panel edid can be
> re-used such as getting multiple get_modes() without irq_hpd and
> should be cleared in cases when the connector is destroyed or when
> irq hpd is received. Add support to handle these cases for the
> mst_connector's panel edid.
> 
> Signed-off-by: Abhinav Kumar <quic_abhinavk@...cinc.com>
> ---
>  drivers/gpu/drm/msm/dp/dp_mst_drm.c | 39 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_mst_drm.c b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
> index 2d92084586b466d4953429e8a6fbf766d081cb9f..15c61fd37c418889074222c0f576778adadf51c9 100644
> --- a/drivers/gpu/drm/msm/dp/dp_mst_drm.c
> +++ b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
> @@ -559,6 +559,34 @@ static struct msm_dp_mst_bridge_state *msm_dp_mst_br_priv_state(struct drm_atomi
>  										&bridge->obj));
>  }
>  
> +static void msm_dp_mst_clear_panel_edid(struct msm_dp *dp_display)
> +{
> +	struct msm_dp_mst *mst = dp_display->msm_dp_mst;
> +	struct msm_dp_mst_connector *mst_conn;
> +	struct msm_dp_panel *dp_panel;
> +	struct msm_dp_mst_bridge *dp_bridge;
> +	int i;
> +
> +	if (!dp_display) {
> +		DRM_ERROR("invalid input\n");
> +		return;
> +	}

Drop

> +
> +	for (i = 0; i < mst->max_streams; i++) {
> +		dp_bridge = &mst->mst_bridge[i];
> +		mst_conn = to_msm_dp_mst_connector(dp_bridge->connector);
> +		dp_panel = dp_bridge->msm_dp_panel;
> +
> +		if (!dp_panel || !mst_conn || !mst_conn->mst_port)
> +			continue;
> +
> +		if (dp_panel->drm_edid) {
> +			drm_edid_free(dp_panel->drm_edid);
> +			dp_panel->drm_edid = NULL;
> +		}
> +	}
> +}
> +
>  /* DP MST HPD IRQ callback */
>  void msm_dp_mst_display_hpd_irq(struct msm_dp *dp_display)
>  {
> @@ -585,6 +613,9 @@ void msm_dp_mst_display_hpd_irq(struct msm_dp *dp_display)
>  	if (handled) {
>  		rc = drm_dp_dpcd_writeb(mst->dp_aux, esi_res, ack[1]);
>  
> +		if (ack[1] & DP_UP_REQ_MSG_RDY)
> +			msm_dp_mst_clear_panel_edid(dp_display);
> +
>  		if (rc != 1)
>  			DRM_ERROR("dpcd esi_res failed. rc=%d\n", rc);
>  
> @@ -620,6 +651,9 @@ static int msm_dp_mst_connector_get_modes(struct drm_connector *connector)
>  	struct msm_dp_mst *mst = dp_display->msm_dp_mst;
>  	struct msm_dp_panel *dp_panel = mst_conn->dp_panel;
>  
> +	if (dp_panel->drm_edid)
> +		goto duplicate_edid;
> +
>  	drm_edid_free(dp_panel->drm_edid);
>  
>  	dp_panel->drm_edid = drm_dp_mst_edid_read(connector, &mst->mst_mgr, mst_conn->mst_port);
> @@ -628,6 +662,7 @@ static int msm_dp_mst_connector_get_modes(struct drm_connector *connector)
>  		return -EINVAL;
>  	}
>  
> +duplicate_edid:
>  	drm_edid_connector_update(connector, dp_panel->drm_edid);

No need to update connector. Goto to the next line instead.

>  
>  	return drm_edid_connector_add_modes(connector);
> @@ -894,6 +929,10 @@ static int msm_dp_mst_connector_atomic_check(struct drm_connector *connector,
>  static void dp_mst_connector_destroy(struct drm_connector *connector)
>  {
>  	struct msm_dp_mst_connector *mst_conn = to_msm_dp_mst_connector(connector);
> +	struct msm_dp_panel *dp_panel = mst_conn->dp_panel;
> +
> +	drm_edid_free(dp_panel->drm_edid);
> +	dp_panel->drm_edid = NULL;
>  
>  	drm_connector_cleanup(connector);
>  	drm_dp_mst_put_port_malloc(mst_conn->mst_port);
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry