From 1f73b8b56cf35de29a433aee7bfff26cea98be3f Mon Sep 17 00:00:00 2001 From: =?utf8?q?=C5=81ukasz=20Bartosik?= Date: Wed, 19 Nov 2025 21:29:09 +0000 Subject: [PATCH] xhci: dbgtty: fix device unregister MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When DbC is disconnected then xhci_dbc_tty_unregister_device() is called. However if there is any user space process blocked on write to DbC terminal device then it will never be signalled and thus stay blocked indifinitely. This fix adds a tty_vhangup() call in xhci_dbc_tty_unregister_device(). The tty_vhangup() wakes up any blocked writers and causes subsequent write attempts to DbC terminal device to fail. Cc: stable Fixes: dfba2174dc42 ("usb: xhci: Add DbC support in xHCI driver") Signed-off-by: Łukasz Bartosik Link: https://patch.msgid.link/20251119212910.1245694-1-ukaszb@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-dbgtty.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c index b7f95565524d9..57cdda4e09c8e 100644 --- a/drivers/usb/host/xhci-dbgtty.c +++ b/drivers/usb/host/xhci-dbgtty.c @@ -550,6 +550,12 @@ static void xhci_dbc_tty_unregister_device(struct xhci_dbc *dbc) if (!port->registered) return; + /* + * Hang up the TTY. This wakes up any blocked + * writers and causes subsequent writes to fail. + */ + tty_vhangup(port->port.tty); + tty_unregister_device(dbc_tty_driver, port->minor); xhci_dbc_tty_exit_port(port); port->registered = false; -- 2.47.3