[Intel-gfx] [PATCH 15/44] drm/udl: Use demv_drm_dev_alloc

[Noralf Trønnes]

Den 03.04.2020 15.57, skrev Daniel Vetter:
> Also init the fbdev emulation before we register the device, that way
> we can rely on the auto-cleanup and simplify the probe error code even
> more.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Dave Airlie <airlied at redhat.com>
> Cc: Sean Paul <sean at poorly.run>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Emil Velikov <emil.l.velikov at gmail.com>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Thomas Gleixner <tglx at linutronix.de>
> ---
>  drivers/gpu/drm/udl/udl_drv.c | 36 +++++++++++------------------------
>  1 file changed, 11 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c
> index 1ce2d865c36d..4ba5149fdd57 100644
> --- a/drivers/gpu/drm/udl/udl_drv.c
> +++ b/drivers/gpu/drm/udl/udl_drv.c
> @@ -57,27 +57,20 @@ static struct udl_device *udl_driver_create(struct usb_interface *interface)
>  	struct udl_device *udl;
>  	int r;
>  
> -	udl = kzalloc(sizeof(*udl), GFP_KERNEL);
> -	if (!udl)
> -		return ERR_PTR(-ENOMEM);
> -
> -	r = drm_dev_init(&udl->drm, &driver, &interface->dev);
> -	if (r) {
> -		kfree(udl);
> -		return ERR_PTR(r);
> -	}
> +	udl = devm_drm_dev_alloc(&interface->dev, &driver,
> +				 struct udl_device, drm);
> +	if (IS_ERR(udl))
> +		return udl;
>  
>  	udl->udev = udev;
>  	udl->drm.dev_private = udl;
> -	drmm_add_final_kfree(&udl->drm, udl);
>  
>  	r = udl_init(udl);
> -	if (r) {
> -		drm_dev_put(&udl->drm);
> +	if (r)
>  		return ERR_PTR(r);
> -	}
>  
>  	usb_set_intfdata(interface, udl);
> +
>  	return udl;
>  }
>  
> @@ -91,23 +84,17 @@ static int udl_usb_probe(struct usb_interface *interface,
>  	if (IS_ERR(udl))
>  		return PTR_ERR(udl);
>  
> +	r = drm_fbdev_generic_setup(&udl->drm, 0);

It doesn't feel right to have a client open the device before the DRM
device itself is registered. I would prefer to keep it where it is but
ignore any errors. A failing client shouldn't prevent the driver from
probing. drm_fbdev_generic_setup() do print errors if it fails. So yeah,
in hindsight I should have made drm_fbdev_generic_setup() return void.

Noralf.

> +	if (r)
> +		return r;
> +
>  	r = drm_dev_register(&udl->drm, 0);
>  	if (r)
> -		goto err_free;
> +		return r;
>  
>  	DRM_INFO("Initialized udl on minor %d\n", udl->drm.primary->index);
>  
> -	r = drm_fbdev_generic_setup(&udl->drm, 0);
> -	if (r)
> -		goto err_drm_dev_unregister;
> -
>  	return 0;
> -
> -err_drm_dev_unregister:
> -	drm_dev_unregister(&udl->drm);
> -err_free:
> -	drm_dev_put(&udl->drm);
> -	return r;
>  }
>  
>  static void udl_usb_disconnect(struct usb_interface *interface)
> @@ -117,7 +104,6 @@ static void udl_usb_disconnect(struct usb_interface *interface)
>  	drm_kms_helper_poll_fini(dev);
>  	udl_drop_usb(dev);
>  	drm_dev_unplug(dev);
> -	drm_dev_put(dev);
>  }
>  
>  /*
>