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Message-ID: <63412979-d7fa-4147-8c38-f576503a3173@linaro.org>
Date:   Tue, 28 Nov 2023 09:24:28 +0100
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From:   Neil Armstrong <neil.armstrong@linaro.org>
Reply-To: neil.armstrong@linaro.org
Subject: Re: [PATCH 2/3] Revert "drm/bridge: panel: Check device dependency
 before managing device link"
Content-Language: en-US, fr
To:     Linus Walleij <linus.walleij@linaro.org>,
        Liu Ying <victor.liu@nxp.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Andrzej Hajda <andrzej.hajda@intel.com>,
        Robert Foss <rfoss@kernel.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>
Cc:     linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
References: <20231128-revert-panel-fix-v1-0-69bb05048dae@linaro.org>
 <20231128-revert-panel-fix-v1-2-69bb05048dae@linaro.org>
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In-Reply-To: <20231128-revert-panel-fix-v1-2-69bb05048dae@linaro.org>
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On 28/11/2023 00:10, Linus Walleij wrote:
> This reverts commit 39d5b6a64ace77d0c11c398d272218df5f939abb.
> 
> This patch was causing build errors by using an unexported
> function from the device core, which Greg questions the
> saneness in exporting.
> 
> Link: https://lore.kernel.org/lkml/CACRpkdaGzXD6HbiX7mVUNJAJtMEPG00Pp6+nJ1P0JrfJ-ArMvQ@mail.gmail.com/T/
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>   drivers/gpu/drm/bridge/panel.c | 27 +++++++++------------------
>   1 file changed, 9 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
> index 5e8980023407..e48823a4f1ed 100644
> --- a/drivers/gpu/drm/bridge/panel.c
> +++ b/drivers/gpu/drm/bridge/panel.c
> @@ -23,7 +23,6 @@ struct panel_bridge {
>   	struct drm_panel *panel;
>   	struct device_link *link;
>   	u32 connector_type;
> -	bool is_independent;
>   };
>   
>   static inline struct panel_bridge *
> @@ -68,17 +67,12 @@ static int panel_bridge_attach(struct drm_bridge *bridge,
>   	struct drm_device *drm_dev = bridge->dev;
>   	int ret;
>   
> -	panel_bridge->is_independent = !device_is_dependent(drm_dev->dev,
> -							    panel->dev);
> -
> -	if (panel_bridge->is_independent) {
> -		panel_bridge->link = device_link_add(drm_dev->dev, panel->dev,
> -						     DL_FLAG_STATELESS);
> -		if (!panel_bridge->link) {
> -			DRM_ERROR("Failed to add device link between %s and %s\n",
> -				  dev_name(drm_dev->dev), dev_name(panel->dev));
> -			return -EINVAL;
> -		}
> +	panel_bridge->link = device_link_add(drm_dev->dev, panel->dev,
> +					     DL_FLAG_STATELESS);
> +	if (!panel_bridge->link) {
> +		DRM_ERROR("Failed to add device link between %s and %s\n",
> +			  dev_name(drm_dev->dev), dev_name(panel->dev));
> +		return -EINVAL;
>   	}
>   
>   	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
> @@ -86,8 +80,7 @@ static int panel_bridge_attach(struct drm_bridge *bridge,
>   
>   	if (!bridge->encoder) {
>   		DRM_ERROR("Missing encoder\n");
> -		if (panel_bridge->is_independent)
> -			device_link_del(panel_bridge->link);
> +		device_link_del(panel_bridge->link);
>   		return -ENODEV;
>   	}
>   
> @@ -99,8 +92,7 @@ static int panel_bridge_attach(struct drm_bridge *bridge,
>   				 panel_bridge->connector_type);
>   	if (ret) {
>   		DRM_ERROR("Failed to initialize connector\n");
> -		if (panel_bridge->is_independent)
> -			device_link_del(panel_bridge->link);
> +		device_link_del(panel_bridge->link);
>   		return ret;
>   	}
>   
> @@ -123,8 +115,7 @@ static void panel_bridge_detach(struct drm_bridge *bridge)
>   	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
>   	struct drm_connector *connector = &panel_bridge->connector;
>   
> -	if (panel_bridge->is_independent)
> -		device_link_del(panel_bridge->link);
> +	device_link_del(panel_bridge->link);
>   
>   	/*
>   	 * Cleanup the connector if we know it was initialized.
> 

Acked-by: Neil Armstrong <neil.armstrong@linaro.org>