This is a note to let you know that I've just added the patch titled USB: serial: ch341: fix modem-control and B0 handling to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-serial-ch341-fix-modem-control-and-b0-handling.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 030ee7ae52a46a2be52ccc8242c4a330aba8d38e Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan@xxxxxxxxxx> Date: Fri, 6 Jan 2017 19:15:12 +0100 Subject: USB: serial: ch341: fix modem-control and B0 handling From: Johan Hovold <johan@xxxxxxxxxx> commit 030ee7ae52a46a2be52ccc8242c4a330aba8d38e upstream. 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") Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/serial/ch341.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -362,24 +362,24 @@ static void ch341_set_termios(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) Patches currently in stable-queue which might be from johan@xxxxxxxxxx are queue-4.9/usb-serial-ch341-fix-modem-control-and-b0-handling.patch queue-4.9/powerpc-ibmebus-fix-further-device-reference-leaks.patch queue-4.9/usb-serial-ch341-fix-control-message-error-handling.patch queue-4.9/usb-serial-ch341-fix-open-and-resume-after-b0.patch queue-4.9/usb-serial-ch341-fix-open-error-handling.patch queue-4.9/usb-serial-ch341-fix-initial-modem-control-state.patch queue-4.9/bus-vexpress-config-fix-device-reference-leak.patch queue-4.9/powerpc-ibmebus-fix-device-reference-leaks-in-sysfs-interface.patch queue-4.9/usb-serial-kl5kusb105-fix-line-state-error-handling.patch queue-4.9/usb-serial-ch341-fix-resume-after-reset.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html