[PATCH 1/3] drm/udl: Unregister device before cleaning up on disconnect

[Patrik Jakobsson]

On Mon, Mar 3, 2025 at 4:09 PM Thomas Zimmermann <tzimmermann at suse.de> wrote:
>
> Disconnecting a DisplayLink device results in the following kernel
> error messages
>
> [   93.041748] [drm:udl_urb_completion [udl]] *ERROR* udl_urb_completion - nonzero write bulk status received: -115
> [   93.055299] [drm:udl_submit_urb [udl]] *ERROR* usb_submit_urb error fffffffe
> [   93.065363] [drm:udl_urb_completion [udl]] *ERROR* udl_urb_completion - nonzero write bulk status received: -115
> [   93.078207] [drm:udl_submit_urb [udl]] *ERROR* usb_submit_urb error fffffffe
>
> coming from KMS poll helpers. Shutting down poll helpers runs them
> one final time when the USB device is already gone.
>
> Run drm_dev_unplug() first in udl's USB disconnect handler. Udl's
> polling code already handles disconnects gracefully if the device has
> been marked as unplugged.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> Fixes: b1a981bd5576 ("drm/udl: drop drm_driver.release hook")
> Cc: dri-devel at lists.freedesktop.org
> Cc: <stable at vger.kernel.org> # v5.8+

Hi Thomas,
Looks good.

Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson at gmail.com>

> ---
>  drivers/gpu/drm/udl/udl_drv.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c
> index 05b3a152cc33..7e7d704be0c0 100644
> --- a/drivers/gpu/drm/udl/udl_drv.c
> +++ b/drivers/gpu/drm/udl/udl_drv.c
> @@ -127,9 +127,9 @@ static void udl_usb_disconnect(struct usb_interface *interface)
>  {
>         struct drm_device *dev = usb_get_intfdata(interface);
>
> +       drm_dev_unplug(dev);
>         drm_kms_helper_poll_fini(dev);
>         udl_drop_usb(dev);
> -       drm_dev_unplug(dev);
>  }
>
>  /*
> --
> 2.48.1
>