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patch "USB: serial: ch341: fix modem-control and B0 handling" added to usb-linus

PATCH [email protected] 1 participant 1 message Jan 12, 2017

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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 my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

Quoted 1 line

From 030ee7ae52a46a2be52ccc8242c4a330aba8d38e Mon Sep 17 00:00:00 2001

From: Johan Hovold <[email protected]>
Date: Fri, 6 Jan 2017 19:15:12 +0100
Subject: 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 <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
---
 drivers/usb/serial/ch341.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)
drivers/usb/serial/ch341.c +7 -9
index 6279df905c14..0cc5056b304d 100644
@@ -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)
Signature · 1 line
2.11.0