Re: [PATCH 6.12 493/567] xhci: dbgtty: fix device unregister: fixup

Łukasz Bartosik
2026-01-07T00:04:51Z

On Tue, Jan 6, 2026 at 6:43 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> 6.12-stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: Łukasz Bartosik <ukaszb@chromium.org>
>
> [ Upstream commit 74098cc06e753d3ffd8398b040a3a1dfb65260c0 ]
>
> 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>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
> drivers/usb/host/xhci-dbgtty.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/drivers/usb/host/xhci-dbgtty.c
> +++ b/drivers/usb/host/xhci-dbgtty.c
> @@ -522,7 +522,7 @@ static void xhci_dbc_tty_unregister_devi
> * 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);

The function tty_port_tty_vhangup does not exist in the 6.12 kernel.
It was added later.

I sent updated patch
https://lore.kernel.org/stable/20260106235820.2995848-1-ukaszb@chromium.org/T/#mb46d870145474d04aaabeccc76aaf949b34bbf86

Thanks,
Łukasz

>
> tty_unregister_device(dbc_tty_driver, port->minor);
> xhci_dbc_tty_exit_port(port);
>
>