[PATCH 3.10 085/250] USB: serial: ch341: fix open and resume after B0

From: Willy Tarreau
Date: Wed Jun 07 2017 - 19:04:13 EST


From: Johan Hovold <johan@xxxxxxxxxx>

commit a20047f36e2f6a1eea4f1fd261aaa55882369868 upstream.

The private baud_rate variable is used to configure the port at open and
reset-resume and must never be set to (and left at) zero or reset-resume
and all further open attempts will fail.

Fixes: aa91def41a7b ("USB: ch341: set tty baud speed according to tty struct")
Fixes: 664d5df92e88 ("USB: usb-serial ch341: support for DTR/RTS/CTS")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
drivers/usb/serial/ch341.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index db37b16..e9cfd40 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -368,12 +368,11 @@ static void ch341_set_termios(struct tty_struct *tty,

baud_rate = tty_get_baud_rate(tty);

- priv->baud_rate = baud_rate;
-
if (baud_rate) {
spin_lock_irqsave(&priv->lock, flags);
priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
spin_unlock_irqrestore(&priv->lock, flags);
+ priv->baud_rate = baud_rate;
ch341_set_baudrate(port->serial->dev, priv);
} else {
spin_lock_irqsave(&priv->lock, flags);
--
2.8.0.rc2.1.gbe9624a