From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39432 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752316AbdLFQcM (ORCPT ); Wed, 6 Dec 2017 11:32:12 -0500 Subject: Patch "serial: 8250: Preserve DLD[7:4] for PORT_XR17V35X" has been added to the 4.4-stable tree To: asierra@xes-inc.com, alexander.levin@verizon.com, gregkh@linuxfoundation.org Cc: , From: Date: Wed, 06 Dec 2017 17:31:36 +0100 Message-ID: <1512577896120163@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled serial: 8250: Preserve DLD[7:4] for PORT_XR17V35X to the 4.4-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: serial-8250-preserve-dld-for-port_xr17v35x.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Wed Dec 6 16:43:17 CET 2017 From: Aaron Sierra Date: Wed, 4 Oct 2017 10:01:28 -0500 Subject: serial: 8250: Preserve DLD[7:4] for PORT_XR17V35X From: Aaron Sierra [ Upstream commit 0ab84da2e076948c49d36197ee7d254125c53eab ] The upper four bits of the XR17V35x fractional divisor register (DLD) control general chip function (RS-485 direction pin polarity, multidrop mode, XON/XOFF parity check, and fast IR mode). Don't allow these bits to be clobbered when setting the baudrate. Signed-off-by: Aaron Sierra Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -2223,8 +2223,11 @@ static void serial8250_set_divisor(struc serial_dl_write(up, quot); /* XR17V35x UARTs have an extra fractional divisor register (DLD) */ - if (up->port.type == PORT_XR17V35X) + if (up->port.type == PORT_XR17V35X) { + /* Preserve bits not related to baudrate; DLD[7:4]. */ + quot_frac |= serial_port_in(port, 0x2) & 0xf0; serial_port_out(port, 0x2, quot_frac); + } } static unsigned int Patches currently in stable-queue which might be from asierra@xes-inc.com are queue-4.4/serial-8250-preserve-dld-for-port_xr17v35x.patch