[PATCH 6.1 105/132] drm/udl: Unregister device before cleaning up on disconnect

Greg Kroah-Hartman gregkh at linuxfoundation.org
Thu Jul 3 14:43:14 UTC 2025


6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thomas Zimmermann <tzimmermann at suse.de>

commit ff9cb6d2035c586ea7c8f1754d4409eec7a2d26d upstream.

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+
Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson at gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250303145604.62962-2-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/gpu/drm/udl/udl_drv.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/udl/udl_drv.c
+++ b/drivers/gpu/drm/udl/udl_drv.c
@@ -126,9 +126,9 @@ static void udl_usb_disconnect(struct us
 {
 	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);
 }
 
 /*




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