From: Johan Hovold <johan@kernel.org> [ Upstream commit 60c6b305c11b5fd167ce5e2ce42f3a9098c388f0 ] TIOCSSERIAL is a horrid, underspecified, legacy interface which for most serial devices is only useful for setting the close_delay and closing_wait parameters. A non-privileged user has only ever been able to set the since long deprecated ASYNC_SPD flags and trying to change any other *supported* feature should result in -EPERM being returned. Setting the current values for any supported features should return success. Fix the greybus implementation which instead indicated that the TIOCSSERIAL ioctl was not even implemented when a non-privileged user set the current values. Fixes: e68453ed28c5 ("greybus: uart-gb: now builds, more framework added") Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210407102334.32361-7-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/staging/greybus/uart.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/staging/greybus/uart.c b/drivers/staging/greybus/uart.c index f36d470aed241..2343914f7548a 100644 --- a/drivers/staging/greybus/uart.c +++ b/drivers/staging/greybus/uart.c @@ -656,8 +656,6 @@ static int set_serial_info(struct gb_tty *gb_tty, if ((close_delay != gb_tty->port.close_delay) || (closing_wait != gb_tty->port.closing_wait)) retval = -EPERM; - else - retval = -EOPNOTSUPP; } else { gb_tty->port.close_delay = close_delay; gb_tty->port.closing_wait = closing_wait; -- 2.25.1