linux-kernel - Re: [PATCH] drm/bridge: Fix lvds-encoder since the panel

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20171115105958.4941720c@karo-electronics.de>
Date:   Wed, 15 Nov 2017 10:59:58 +0100
From:   Lothar Waßmann <LW@...O-electronics.de>
To:     Eric Anholt <eric@...olt.net>
Cc:     dri-devel@...ts.freedesktop.org,
        Archit Taneja <architt@...eaurora.org>,
        Andrzej Hajda <a.hajda@...sung.com>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drm/bridge: Fix lvds-encoder since the panel_bridge
 rework.

Hi,

On Tue, 14 Nov 2017 11:16:47 -0800 Eric Anholt wrote:
> The panel_bridge bridge attaches to the panel's OF node, not the
> lvds-encoder's node.  Put in a little no-op bridge of our own so that
> our consumers can still find a bridge where they expect.
> 
> This also fixes an unintended unregistration and leak of the
> panel-bridge on module remove.
> 
> Signed-off-by: Eric Anholt <eric@...olt.net>
> Fixes: 13dfc0540a57 ("drm/bridge: Refactor out the panel wrapper from the lvds-encoder bri
> dge.")
> ---
> 
> Note: I haven't actually tested this patch!  Hope it helps, though.
> 
>  drivers/gpu/drm/bridge/lvds-encoder.c | 48 ++++++++++++++++++++++++++++++-----
>  1 file changed, 41 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c b/drivers/gpu/drm/bridge/lvds-encoder.c
> index 0903ba574f61..75b0d3f6e4de 100644
> --- a/drivers/gpu/drm/bridge/lvds-encoder.c
> +++ b/drivers/gpu/drm/bridge/lvds-encoder.c
> @@ -13,13 +13,37 @@
>  
>  #include <linux/of_graph.h>
>  
> +struct lvds_encoder {
> +	struct drm_bridge bridge;
> +	struct drm_bridge *panel_bridge;
> +};
> +
> +static int lvds_encoder_attach(struct drm_bridge *bridge)
> +{
> +	struct lvds_encoder *lvds_encoder = container_of(bridge,
> +							 struct lvds_encoder,
> +							 bridge);
> +
> +	return drm_bridge_attach(bridge->encoder, lvds_encoder->panel_bridge,
> +				 bridge);
> +}
> +
> +static struct drm_bridge_funcs funcs = {
> +	.attach = lvds_encoder_attach,
> +};
> +
>  static int lvds_encoder_probe(struct platform_device *pdev)
>  {
>  	struct device_node *port;
>  	struct device_node *endpoint;
>  	struct device_node *panel_node;
>  	struct drm_panel *panel;
> -	struct drm_bridge *bridge;
> +	struct lvds_encoder *lvds_encoder;
> +
> +	lvds_encoder = devm_kzalloc(&pdev->dev, sizeof(*lvds_encoder),
> +				    GFP_KERNEL);
> +	if (!lvds_encoder)
> +		return -ENOMEM;
>  
>  	/* Locate the panel DT node. */
>  	port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
> @@ -49,20 +73,30 @@ static int lvds_encoder_probe(struct platform_device *pdev)
>  		return -EPROBE_DEFER;
>  	}
>  
> -	bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_LVDS);
> -	if (IS_ERR(bridge))
> -		return PTR_ERR(bridge);
> +	lvds_encoder->panel_bridge =
> +		devm_drm_panel_bridge_add(&pdev->dev,
> +					  panel, DRM_MODE_CONNECTOR_LVDS);
> +	if (IS_ERR(lvds_encoder->panel_bridge))
> +		return PTR_ERR(lvds_encoder->panel_bridge);
> +
> +	/* The panel_bridge bridge is attached to the panel's of_node,
> +	 * but we need a bridge attached to our of_node for our user
> +	 * to look up.
> +	 */
> +	lvds_encoder->bridge.of_node = pdev->dev.of_node;
> +	lvds_encoder->bridge.funcs = &funcs;
> +	drm_bridge_add(&lvds_encoder->bridge);
>  
> -	platform_set_drvdata(pdev, bridge);
> +	platform_set_drvdata(pdev, lvds_encoder);
>  
>  	return 0;
>  }
>  
>  static int lvds_encoder_remove(struct platform_device *pdev)
>  {
> -	struct drm_bridge *bridge = platform_get_drvdata(pdev);
> +	struct lvds_encoder *lvds_encoder = platform_get_drvdata(pdev);
>  
> -	drm_bridge_remove(bridge);
> +	drm_bridge_remove(&lvds_encoder->bridge);
>  
>  	return 0;
>  }
>
Tested-by: Lothar Waßmann <LW@...O-electronics.de>


Lothar Waßmann