linux-kernel - Re: [PATCH v3] drm/msm/dp: call dp_hpd_plug_handle()/unplug

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Date: Sun, 7 Apr 2024 13:48:34 -0500
From: Bjorn Andersson <andersson@...nel.org>
To: Abhinav Kumar <quic_abhinavk@...cinc.com>
Cc: freedreno@...ts.freedesktop.org, Rob Clark <robdclark@...il.com>, 
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, Sean Paul <sean@...rly.run>, 
	Marijn Suijten <marijn.suijten@...ainline.org>, David Airlie <airlied@...il.com>, 
	Daniel Vetter <daniel@...ll.ch>, Kuogee Hsieh <quic_khsieh@...cinc.com>, 
	dri-devel@...ts.freedesktop.org, seanpaul@...omium.org, swboyd@...omium.org, 
	quic_jesszhan@...cinc.com, quic_bjorande@...cinc.com, johan@...nel.org, 
	linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] drm/msm/dp: call dp_hpd_plug_handle()/unplug_handle()
 directly for external HPD

On Fri, Apr 05, 2024 at 08:15:47PM -0700, Abhinav Kumar wrote:
> From: Kuogee Hsieh <quic_khsieh@...cinc.com>
[..]
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index d80f89581760..bfb6dfff27e8 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -1665,7 +1665,7 @@ void dp_bridge_hpd_notify(struct drm_bridge *bridge,
>  		return;
>  
>  	if (!dp_display->link_ready && status == connector_status_connected)
> -		dp_add_event(dp, EV_HPD_PLUG_INT, 0, 0);
> +		dp_hpd_plug_handle(dp, 0);

If I read the code correctly, and we get an external connect event
inbetween a previous disconnect and the related disable call, this
should result in a PLUG_INT being injected into the queue still.

Will that not cause the same problem?

Regards,
Bjorn

>  	else if (dp_display->link_ready && status == connector_status_disconnected)
> -		dp_add_event(dp, EV_HPD_UNPLUG_INT, 0, 0);
> +		dp_hpd_unplug_handle(dp, 0);
>  }
> -- 
> 2.43.2
>