diff options
| -rw-r--r-- | drivers/tty/tty_io.c | 3 | ||||
| -rw-r--r-- | drivers/usb/class/cdc-acm.c | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 06414e43e0b5..96617f9af819 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2489,6 +2489,9 @@ static int send_break(struct tty_struct *tty, unsigned int duration) if (!retval) { msleep_interruptible(duration); retval = tty->ops->break_ctl(tty, 0); + } else if (retval == -EOPNOTSUPP) { + /* some drivers can tell only dynamically */ + retval = 0; } tty_write_unlock(tty); diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index a1f4e1ead97f..0e7439dba8fe 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -916,6 +916,9 @@ static int acm_tty_break_ctl(struct tty_struct *tty, int state) struct acm *acm = tty->driver_data; int retval; + if (!(acm->ctrl_caps & USB_CDC_CAP_BRK)) + return -EOPNOTSUPP; + retval = acm_send_break(acm, state ? 0xffff : 0); if (retval < 0) dev_dbg(&acm->control->dev, |