linux-kernel - Re: [PATCH] drm/bridge_connector: enable HPD by default if supported

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Message-Id: <5WJ88R.LXNASHJRBDGL1@crapouillou.net>
Date:   Fri, 04 Mar 2022 19:38:29 +0000
From:   Paul Cercueil <paul@...pouillou.net>
To:     Nikita Yushchenko <nikita.yoush@...entembedded.com>
Cc:     Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Kieran Bingham <kieran.bingham+renesas@...asonboard.com>,
        Laurent Pinchart <laurent.pinchart+renesas@...asonboard.com>,
        Jacopo Mondi <jacopo+renesas@...ndi.org>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drm/bridge_connector: enable HPD by default if supported

Hi Nikita,

Le sam., déc. 25 2021 at 09:31:51 +0300, Nikita Yushchenko 
<nikita.yoush@...entembedded.com> a écrit :
> Hotplug events reported by bridge drivers over drm_bridge_hpd_notify()
> get ignored unless somebody calls drm_bridge_hpd_enable(). When the
> connector for the bridge is bridge_connector, such a call is done from
> drm_bridge_connector_enable_hpd().
> 
> However drm_bridge_connector_enable_hpd() is never called on init 
> paths,
> documentation suggests that it is intended for suspend/resume paths.
> 
> In result, once encoders are switched to bridge_connector,
> bridge-detected HPD stops working.
> 
> This patch adds a call to that API on init path.
> 
> This fixes HDMI HPD with rcar-du + adv7513 case when adv7513 reports 
> HPD
> events via interrupts.
> 
> Fixes: c24110a8fd09 ("drm: rcar-du: Use drm_bridge_connector_init() 
> helper")
> Signed-off-by: Nikita Yushchenko <nikita.yoush@...entembedded.com>

Merged to drm-misc-next.

Thanks!

Cheers,
-Paul

> ---
>  drivers/gpu/drm/drm_bridge_connector.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_bridge_connector.c 
> b/drivers/gpu/drm/drm_bridge_connector.c
> index 791379816837..4f20137ef21d 100644
> --- a/drivers/gpu/drm/drm_bridge_connector.c
> +++ b/drivers/gpu/drm/drm_bridge_connector.c
> @@ -369,8 +369,10 @@ struct drm_connector 
> *drm_bridge_connector_init(struct drm_device *drm,
>  				    connector_type, ddc);
>  	drm_connector_helper_add(connector, 
> &drm_bridge_connector_helper_funcs);
> 
> -	if (bridge_connector->bridge_hpd)
> +	if (bridge_connector->bridge_hpd) {
>  		connector->polled = DRM_CONNECTOR_POLL_HPD;
> +		drm_bridge_connector_enable_hpd(connector);
> +	}
>  	else if (bridge_connector->bridge_detect)
>  		connector->polled = DRM_CONNECTOR_POLL_CONNECT
>  				  | DRM_CONNECTOR_POLL_DISCONNECT;
> --
> 2.30.2