USB: cdc-acm: fix break reporting

commit 58fc1daa4d2e9789b9ffc880907c961ea7c062cc upstream.

A recent change that started reporting break events forgot to push the
event to the line discipline, which meant that a detected break would
not be reported until further characters had been receive (the port
could even have been closed and reopened in between).

Fixes: 08dff274edda ("cdc-acm: fix BREAK rx code path adding necessary calls")
Cc: stable@vger.kernel.org
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210929090937.7410-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 768b920e358f8530621aa933be18abff61066816..b7b83ca83ba0d73a95875809ae5ccd0a3a790b14 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -349,6 +349,9 @@ static void acm_ctrl_irq(struct urb *urb)
                        acm->iocount.overrun++;
                spin_unlock(&acm->read_lock);
 
+               if (newctrl & ACM_CTRL_BRK)
+                       tty_flip_buffer_push(&acm->port);
+
                if (difference)
                        wake_up_all(&acm->wioctl);