FAILED: patch "[PATCH] xhci: dbgtty: fix device unregister: fixup" failed to apply to 6.6-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 74098cc06e753d3ffd8398b040a3a1dfb65260c0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025122917-keenly-greyhound-4fa6@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 74098cc06e753d3ffd8398b040a3a1dfb65260c0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Bartosik?= <ukaszb@chromium.org>
Date: Thu, 27 Nov 2025 11:16:44 +0000
Subject: [PATCH] xhci: dbgtty: fix device unregister: fixup
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This fixup replaces tty_vhangup() call with call to
tty_port_tty_vhangup(). Both calls hangup tty device
synchronously however tty_port_tty_vhangup() increases
reference count during the hangup operation using
scoped_guard(tty_port_tty).

Cc: stable <stable@kernel.org>
Fixes: 1f73b8b56cf3 ("xhci: dbgtty: fix device unregister")
Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
Link: https://patch.msgid.link/20251127111644.3161386-1-ukaszb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c
index 57cdda4e09c8..90282e51e23e 100644
--- a/drivers/usb/host/xhci-dbgtty.c
+++ b/drivers/usb/host/xhci-dbgtty.c
@@ -554,7 +554,7 @@ static void xhci_dbc_tty_unregister_device(struct xhci_dbc *dbc)
 	 * Hang up the TTY. This wakes up any blocked
 	 * writers and causes subsequent writes to fail.
 	 */
-	tty_vhangup(port->port.tty);
+	tty_port_tty_vhangup(&port->port);
 
 	tty_unregister_device(dbc_tty_driver, port->minor);
 	xhci_dbc_tty_exit_port(port);