From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5534CC50731 for ; Fri, 13 Dec 2019 20:37:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95AE224704 for ; Fri, 13 Dec 2019 20:37:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727584AbfLMOET (ORCPT ); Fri, 13 Dec 2019 09:04:19 -0500 Received: from mail.sysgo.com ([176.9.12.79]:58710 "EHLO mail.sysgo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726524AbfLMOES (ORCPT ); Fri, 13 Dec 2019 09:04:18 -0500 From: David Engraf To: richard.genoud@gmail.com, gregkh@linuxfoundation.org, jslaby@suse.com, nicolas.ferre@microchip.com, alexandre.belloni@bootlin.com, ludovic.desroches@microchip.com Cc: linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, David Engraf Subject: [PATCH v2] tty/serial: atmel: fix out of range clock divider handling Date: Fri, 13 Dec 2019 15:03:01 +0100 Message-Id: <20191213140301.16490-1-david.engraf@sysgo.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <1e2e3f63-84db-4b38-1bf1-85916116e0a2@sysgo.com> References: <1e2e3f63-84db-4b38-1bf1-85916116e0a2@sysgo.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use MCK_DIV8 when the clock divider is > 65535. Unfortunately the mode register was already written thus the clock selection is ignored. Fix by doing the baud rate calulation before setting the mode. Fixes: 5bf5635ac170 ("tty/serial: atmel: add fractional baud rate support") Signed-off-by: David Engraf --- drivers/tty/serial/atmel_serial.c | 43 ++++++++++++++++--------------- 1 file changed, 22 insertions(+), 21 deletions(-) diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index a8dc8af83f39..1ba9bc667e13 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -2270,27 +2270,6 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, mode |= ATMEL_US_USMODE_NORMAL; } - /* set the mode, clock divisor, parity, stop bits and data size */ - atmel_uart_writel(port, ATMEL_US_MR, mode); - - /* - * when switching the mode, set the RTS line state according to the - * new mode, otherwise keep the former state - */ - if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) { - unsigned int rts_state; - - if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) { - /* let the hardware control the RTS line */ - rts_state = ATMEL_US_RTSDIS; - } else { - /* force RTS line to low level */ - rts_state = ATMEL_US_RTSEN; - } - - atmel_uart_writel(port, ATMEL_US_CR, rts_state); - } - /* * Set the baud rate: * Fractional baudrate allows to setup output frequency more @@ -2317,6 +2296,28 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, if (!(port->iso7816.flags & SER_ISO7816_ENABLED)) atmel_uart_writel(port, ATMEL_US_BRGR, quot); + + /* set the mode, clock divisor, parity, stop bits and data size */ + atmel_uart_writel(port, ATMEL_US_MR, mode); + + /* + * when switching the mode, set the RTS line state according to the + * new mode, otherwise keep the former state + */ + if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) { + unsigned int rts_state; + + if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) { + /* let the hardware control the RTS line */ + rts_state = ATMEL_US_RTSDIS; + } else { + /* force RTS line to low level */ + rts_state = ATMEL_US_RTSEN; + } + + atmel_uart_writel(port, ATMEL_US_CR, rts_state); + } + atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); atmel_port->tx_stopped = false; -- 2.17.1