Re: [PATCH v3 01/10] drm/client: Test for connectors before sending hotplug event

From: Sam Ravnborg <sam@ravnborg.org>
To: Thomas Zimmermann <tzimmermann@suse.de>
Cc: airlied@gmail.com, daniel@ffwll.ch,
	maarten.lankhorst@linux.intel.com, mripard@kernel.org,
	javierm@redhat.com, linux-samsung-soc@vger.kernel.org,
	linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org,
	dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
	linux-tegra@vger.kernel.org, freedreno@lists.freedesktop.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 01/10] drm/client: Test for connectors before sending hotplug event
Date: Wed, 25 Jan 2023 21:52:14 +0100	[thread overview]
Message-ID: <Y9GWfi4EiCDPa6BJ@ravnborg.org> (raw)
In-Reply-To: <20230125200415.14123-2-tzimmermann@suse.de>

Hi Thomas,

On Wed, Jan 25, 2023 at 09:04:06PM +0100, Thomas Zimmermann wrote:
> Test for connectors in the client code and remove a similar test
> from the generic fbdev emulation. Do nothing if the test fails.
> Not having connectors indicates a driver bug.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
> ---
>  drivers/gpu/drm/drm_client.c        | 5 +++++
>  drivers/gpu/drm/drm_fbdev_generic.c | 5 -----
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 262ec64d4397..09ac191c202d 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -198,6 +198,11 @@ void drm_client_dev_hotplug(struct drm_device *dev)
>  	if (!drm_core_check_feature(dev, DRIVER_MODESET))
>  		return;
>  
> +	if (!dev->mode_config.num_connector) {
> +		drm_dbg_kms(dev, "No connectors found, will not send hotplug events!\n");
> +		return;
This deserves a more visible logging - if a driver fails here it would
be good to spot it in the normal kernel log.
drm_info or drm_notice?

The original code had this on the debug level, but when moving the log
level could also be updated.

	Sam

> +	}
> +
>  	mutex_lock(&dev->clientlist_mutex);
>  	list_for_each_entry(client, &dev->clientlist, list) {
>  		if (!client->funcs || !client->funcs->hotplug)
> diff --git a/drivers/gpu/drm/drm_fbdev_generic.c b/drivers/gpu/drm/drm_fbdev_generic.c
> index 0a4c160e0e58..3d455a2e3fb5 100644
> --- a/drivers/gpu/drm/drm_fbdev_generic.c
> +++ b/drivers/gpu/drm/drm_fbdev_generic.c
> @@ -389,11 +389,6 @@ static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
>  	if (dev->fb_helper)
>  		return drm_fb_helper_hotplug_event(dev->fb_helper);
>  
> -	if (!dev->mode_config.num_connector) {
> -		drm_dbg_kms(dev, "No connectors found, will not create framebuffer!\n");
> -		return 0;
> -	}
> -
>  	drm_fb_helper_prepare(dev, fb_helper, &drm_fb_helper_generic_funcs);
>  
>  	ret = drm_fb_helper_init(dev, fb_helper);
> -- 
> 2.39.0

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