4.9-stable patches

[thirdparty/kernel/stable-queue.git] / releases / 4.6.1 / usb-serial-cp210x-fix-hardware-flow-control-disable.patch

From a377f9e906af4df9071ba8ddba60188cb4013d93 Mon Sep 17 00:00:00 2001
From: Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com>
Date: Wed, 4 May 2016 16:56:52 -0500
Subject: USB: serial: cp210x: fix hardware flow-control disable

From: Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com>

commit a377f9e906af4df9071ba8ddba60188cb4013d93 upstream.

A bug in the CRTSCTS handling caused RTS to alternate between

CRTSCTS=0 => "RTS is transmit active signal" and
CRTSCTS=1 => "RTS is used for receive flow control"

instead of

CRTSCTS=0 => "RTS is statically active" and
CRTSCTS=1 => "RTS is used for receive flow control"

This only happened after first having enabled CRTSCTS.

Signed-off-by: Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com>
Fixes: 39a66b8d22a3 ("[PATCH] USB: CP2101 Add support for flow control")
[johan: reword commit message ]
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/serial/cp210x.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -971,8 +971,7 @@ static void cp210x_set_termios(struct tt
 		} else {
 			modem_ctl[0] &= ~0x7B;
 			modem_ctl[0] |= 0x01;
-			/* FIXME - OR here instead of assignment looks wrong */
-			modem_ctl[4] |= 0x40;
+			modem_ctl[4] = 0x40;
 			dev_dbg(dev, "%s - flow control = NONE\n", __func__);
 		}