diff options
| author | Johan Hovold <johan@kernel.org> | 2017-01-06 19:15:12 +0100 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2017-01-09 14:55:37 +0100 |
| commit | 030ee7ae52a46a2be52ccc8242c4a330aba8d38e (patch) | |
| tree | 859037014f2994e463a04d6ed82abda0851c299c /drivers/usb | |
| parent | a20047f36e2f6a1eea4f1fd261aaa55882369868 (diff) | |
| download | linux-030ee7ae52a46a2be52ccc8242c4a330aba8d38e.tar.bz2 | |
USB: serial: ch341: fix modem-control and B0 handling
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>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/serial/ch341.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index 6279df905c14..0cc5056b304d 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -384,10 +384,6 @@ static void ch341_set_termios(struct tty_struct *tty, ctrl |= CH341_LCR_STOP_BITS_2; 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; r = ch341_init_set_baudrate(port->serial->dev, priv, ctrl); @@ -395,14 +391,16 @@ static void ch341_set_termios(struct tty_struct *tty, priv->baud_rate = tty_termios_baud_rate(old_termios); tty_termios_copy_hw(&tty->termios, old_termios); } - } 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); + 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) |