drm/udl: Unregister device before cleaning up on disconnect

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@suse.de>
Fixes: b1a981bd5576 ("drm/udl: drop drm_driver.release hook")
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250303145604.62962-2-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c
index 3b56ca2f6eb82b4b192815e527b42a852fb36cc8..9a66a1a6781f752065addb138782fd92c2cc2dbb 100644 (file)
--- a/drivers/gpu/drm/udl/udl_drv.c
+++ b/drivers/gpu/drm/udl/udl_drv.c
@@ -110,9 +110,9 @@ 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);
 }
 
 /*