[PATCH v1] xhci: dbctty: disable ECHO flag by default

[PATCH v1] xhci: dbctty: disable ECHO flag by default

[Łukasz Bartosik]

When /dev/ttyDBC0 device is created then by default ECHO flag
is set for the terminal device. However if data arrives from
a peer before application using /dev/ttyDBC0 applies its set
of terminal flags then the arriving data will be echoed which
might not be desired behavior.

Fixes: 4521f1613940 ("xhci: dbctty: split dbc tty driver registration and unregistration functions.")
Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
---
 drivers/usb/host/xhci-dbgtty.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c
index 60ed753c85bb..d894081d8d15 100644
--- a/drivers/usb/host/xhci-dbgtty.c
+++ b/drivers/usb/host/xhci-dbgtty.c
@@ -617,6 +617,7 @@ int dbc_tty_init(void)
 	dbc_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
 	dbc_tty_driver->subtype = SERIAL_TYPE_NORMAL;
 	dbc_tty_driver->init_termios = tty_std_termios;
+	dbc_tty_driver->init_termios.c_lflag &= ~ECHO;
 	dbc_tty_driver->init_termios.c_cflag =
 			B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 	dbc_tty_driver->init_termios.c_ispeed = 9600;
-- 
2.50.0.rc0.642.g800a2b2222-goog

Re: [PATCH v1] xhci: dbctty: disable ECHO flag by default

[kernel test robot]

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-1

Rule: add the tag "Cc: stable@vger.kernel.org" in the sign-off area to have the patch automatically included in the stable tree.
Subject: [PATCH v1] xhci: dbctty: disable ECHO flag by default
Link: https://lore.kernel.org/stable/20250610111802.18742-1-ukaszb%40chromium.org

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki