From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:55430 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753682AbcHRIay (ORCPT ); Thu, 18 Aug 2016 04:30:54 -0400 Subject: Patch "tty/serial: atmel: fix RS485 half duplex with DMA" has been added to the 4.4-stable tree To: alexandre.belloni@free-electrons.com, gregkh@linuxfoundation.org, nicolas.ferre@atmel.com Cc: , From: Date: Thu, 18 Aug 2016 10:30:31 +0200 Message-ID: <1471509031130202@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 tty/serial: atmel: fix RS485 half duplex with DMA 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: tty-serial-atmel-fix-rs485-half-duplex-with-dma.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 0058f0871efe7b01c6f2b3046c68196ab73e96da Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Sat, 28 May 2016 00:54:08 +0200 Subject: tty/serial: atmel: fix RS485 half duplex with DMA From: Alexandre Belloni commit 0058f0871efe7b01c6f2b3046c68196ab73e96da upstream. When using DMA, half duplex doesn't work properly because rx is not stopped before starting tx. Ensure we call atmel_stop_rx() in the DMA case. Signed-off-by: Alexandre Belloni Acked-by: Nicolas Ferre Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/atmel_serial.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -485,19 +485,21 @@ static void atmel_start_tx(struct uart_p { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (atmel_use_pdc_tx(port)) { - if (atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN) - /* The transmitter is already running. Yes, we - really need this.*/ - return; + if (atmel_use_pdc_tx(port) && (atmel_uart_readl(port, ATMEL_PDC_PTSR) + & ATMEL_PDC_TXTEN)) + /* The transmitter is already running. Yes, we + really need this.*/ + return; + if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port)) if ((port->rs485.flags & SER_RS485_ENABLED) && !(port->rs485.flags & SER_RS485_RX_DURING_TX)) atmel_stop_rx(port); + if (atmel_use_pdc_tx(port)) /* re-enable PDC transmit */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN); - } + /* Enable interrupts */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); } Patches currently in stable-queue which might be from alexandre.belloni@free-electrons.com are queue-4.4/tty-serial-atmel-fix-rs485-half-duplex-with-dma.patch