Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752161AbdFGXZj (ORCPT ); Wed, 7 Jun 2017 19:25:39 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:50770 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753396AbdFGXFh (ORCPT ); Wed, 7 Jun 2017 19:05:37 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Johan Hovold , Willy Tarreau Subject: [PATCH 3.10 087/250] USB: serial: ch341: fix modem-control and B0 handling Date: Thu, 8 Jun 2017 00:57:53 +0200 Message-Id: <1496876436-32402-88-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1496876436-32402-1-git-send-email-w@1wt.eu> References: <1496876436-32402-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1965 Lines: 58 From: Johan Hovold 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 Signed-off-by: Willy Tarreau --- drivers/usb/serial/ch341.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index be51cd9..a4e5be5 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -369,24 +369,24 @@ 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) -- 2.8.0.rc2.1.gbe9624a