diff options
| author | Johan Hovold <johan@kernel.org> | 2017-01-06 19:15:12 +0100 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2017-03-06 17:29:15 -0500 |
| commit | c72629ab768645a9b16d263717d88d8c1c56fc3c (patch) | |
| tree | 441209483cd9a6cb22c1a296671b964d3050d9f4 /drivers | |
| parent | f7ee5552dd91c9e4f7d6efd2ae0bb721b67b3da7 (diff) | |
USB: serial: ch341: fix modem-control and B0 handling
[ Upstream commit 030ee7ae52a46a2be52ccc8242c4a330aba8d38e ]
The modem-control signals are managed by the tty-layer during open and
should not be asserted prematurely when set_termios is called from
driver open.
Also make sure that the signals are asserted only when changing speed
from B0.
Fixes: 664d5df92e88 ("USB: usb-serial ch341: support for DTR/RTS/CTS")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/serial/ch341.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index ddb05ee0762b..b9a20523d331 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -345,24 +345,24 @@ static void ch341_set_termios(struct tty_struct *tty, baud_rate = tty_get_baud_rate(tty); 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); - priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS); - spin_unlock_irqrestore(&priv->lock, flags); } - ch341_set_handshake(port->serial->dev, priv->line_control); - /* Unimplemented: * (cflag & CSIZE) : data bits [5, 8] * (cflag & PARENB) : parity {NONE, EVEN, ODD} * (cflag & CSTOPB) : stop bits [1, 2] */ + + spin_lock_irqsave(&priv->lock, flags); + if (C_BAUD(tty) == B0) + priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS); + else if (old_termios && (old_termios->c_cflag & CBAUD) == B0) + priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS); + spin_unlock_irqrestore(&priv->lock, flags); + + ch341_set_handshake(port->serial->dev, priv->line_control); } static void ch341_break_ctl(struct tty_struct *tty, int break_state) |