linux-kernel - Re: [PATCH v5 04/12] drm: bridge: analogix: Destroy connector & encoder when unbinding

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Date:   Fri, 07 Apr 2017 14:01:03 +0200
From:   Andrzej Hajda <a.hajda@...sung.com>
To:     Jeffy Chen <jeffy.chen@...k-chips.com>,
        linux-kernel@...r.kernel.org
Cc:     Marek Vasut <marex@...x.de>,
        Tomeu Vizoso <tomeu.vizoso@...labora.com>,
        briannorris@...omium.org, dianders@...omium.org,
        dri-devel@...ts.freedesktop.org, tfiga@...omium.org,
        zyw@...k-chips.com, Yakir Yang <kuankuan.y@...il.com>
Subject: Re: [PATCH v5 04/12] drm: bridge: analogix: Destroy connector &
 encoder when unbinding

On 06.04.2017 14:31, Jeffy Chen wrote:
> Normally we do this in drm_mode_config_cleanup. But:
> 1/ analogix dp's connector is allocated in bind, and freed after unbind.
> So we need to destroy it in unbind to avoid further access.
> 2/ the drm bridge is attached in bind, and detached in encoder cleanup.
> So we need to destroy encoder in unbind.
>
> Signed-off-by: Jeffy Chen <jeffy.chen@...k-chips.com>

In general drm core should free drm resources, doing it in component can
hurt some day. Maybe it would be good to move some stuff from
bind/unbind to probe/remove if necessary, to allow connector and encoder
to live little bit longer, and be destroyed by drm core. This is just
suggestion, I am not familiar enough with the driver to make stronger
statements :)

Reviewed-by: Andrzej Hajda <a.hajda@...sung.com>

 --
Regards
Andrzej


> ---
>
> Changes in v5: None
> Changes in v4:
> Address Andrzej Hajda <a.hajda@...sung.com>'s comments.
>
> Changes in v3: None
> Changes in v2: None
>
>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index d05ade4..4c758ed 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -1439,6 +1439,8 @@ void analogix_dp_unbind(struct device *dev, struct device *master,
>  	struct analogix_dp_device *dp = dev_get_drvdata(dev);
>  
>  	analogix_dp_bridge_disable(dp->bridge);
> +	dp->connector.funcs->destroy(&dp->connector);
> +	dp->encoder->funcs->destroy(dp->encoder);
>  
>  	if (dp->plat_data->panel) {
>  		if (drm_panel_unprepare(dp->plat_data->panel))