linux-kernel - Re: [PATCH] drm/probe_helper: Don't bother probing when connectors are forced off

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Date:   Mon, 17 Sep 2018 20:55:45 +0300
From:   Ville Syrjälä <ville.syrjala@...ux.intel.com>
To:     Lyude Paul <lyude@...hat.com>
Cc:     dri-devel@...ts.freedesktop.org, Sean Paul <sean@...rly.run>,
        David Airlie <airlied@...ux.ie>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drm/probe_helper: Don't bother probing when connectors
 are forced off

On Mon, Sep 17, 2018 at 01:43:44PM -0400, Lyude Paul wrote:
> Userspace asked them to be forced off, so why would we care about what a
> probe tells us?

I believe there should be force checks in the callers already.
Or are we missing some?

> 
> Signed-off-by: Lyude Paul <lyude@...hat.com>
> ---
>  drivers/gpu/drm/drm_probe_helper.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
> index a1bb157bfdfa..56d2b5dd1f58 100644
> --- a/drivers/gpu/drm/drm_probe_helper.c
> +++ b/drivers/gpu/drm/drm_probe_helper.c
> @@ -269,7 +269,9 @@ drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
>  retry:
>  	ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
>  	if (!ret) {
> -		if (funcs->detect_ctx)
> +		if (connector->force == DRM_FORCE_OFF)
> +			ret = connector_status_disconnected;

connector->force is protected by mode_config.mutex IIRC.

> +		else if (funcs->detect_ctx)
>  			ret = funcs->detect_ctx(connector, &ctx, force);
>  		else if (connector->funcs->detect)
>  			ret = connector->funcs->detect(connector, force);
> @@ -317,6 +319,9 @@ drm_helper_probe_detect(struct drm_connector *connector,
>  	if (ret)
>  		return ret;
>  
> +	if (connector->force == DRM_FORCE_OFF)
> +		return connector_status_disconnected;
> +
>  	if (funcs->detect_ctx)
>  		return funcs->detect_ctx(connector, ctx, force);
>  	else if (connector->funcs->detect)
> -- 
> 2.17.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Ville Syrjälä
Intel

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