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: [PATCH] USB: serial: cp210x: fix hardware flow-control disable
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")
Cc: stable <stable@vger.kernel.org>
[johan: reword commit message ]
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/usb/serial/cp210x.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index dd47823bb014c..fef7a512bff40 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -967,8 +967,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
} 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__);
}
--
2.30.2