From patchwork Fri Aug 21 18:02:38 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 7053161 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: X-Original-To: patchwork-linux-sh@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 218849F344 for ; Fri, 21 Aug 2015 18:03:38 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3459620380 for ; Fri, 21 Aug 2015 18:03:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 095F4203B1 for ; Fri, 21 Aug 2015 18:03:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752363AbbHUSDb (ORCPT ); Fri, 21 Aug 2015 14:03:31 -0400 Received: from baptiste.telenet-ops.be ([195.130.132.51]:57663 "EHLO baptiste.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752502AbbHUSDZ (ORCPT ); Fri, 21 Aug 2015 14:03:25 -0400 Received: from ayla.of.borg ([84.193.93.87]) by baptiste.telenet-ops.be with bizsmtp id 7W3J1r0031t5w8s01W3J3E; Fri, 21 Aug 2015 20:03:22 +0200 Received: from ramsan.of.borg ([192.168.97.29] helo=ramsan) by ayla.of.borg with esmtp (Exim 4.82) (envelope-from ) id 1ZSqer-0007oE-LR; Fri, 21 Aug 2015 20:03:17 +0200 Received: from geert by ramsan with local (Exim 4.82) (envelope-from ) id 1ZSqet-0001q1-F3; Fri, 21 Aug 2015 20:03:19 +0200 From: Geert Uytterhoeven To: Greg Kroah-Hartman , Jiri Slaby Cc: Magnus Damm , Yoshihiro Shimoda , Laurent Pinchart , Nobuhiro Iwamatsu , Yoshihiro Kaneko , Kazuya Mizuguchi , Koji Matsuoka , Wolfram Sang , Guennadi Liakhovetski , linux-serial@vger.kernel.org, linux-sh@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v3 14/33] serial: sh-sci: Improve comments for DMA timeout calculation Date: Fri, 21 Aug 2015 20:02:38 +0200 Message-Id: <1440180177-6924-15-git-send-email-geert+renesas@glider.be> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1440180177-6924-1-git-send-email-geert+renesas@glider.be> References: <1440180177-6924-1-git-send-email-geert+renesas@glider.be> Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Reformat, grammar improvements, use "ms" instead of "msec". Signed-off-by: Geert Uytterhoeven --- v3: - No changes, v2: - New. --- drivers/tty/serial/sh-sci.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 340700a11b152952..cfef543df25271f5 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -2015,13 +2015,13 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, #ifdef CONFIG_SERIAL_SH_SCI_DMA /* * Calculate delay for 2 DMA buffers (4 FIFO). - * See serial_core.c::uart_update_timeout(). With 10 - * bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function - * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)." - * Then below we calculate 5 jiffies (20ms) for 2 DMA buffers (4 FIFO - * sizes), but when performing a faster transfer, value obtained by - * this formula is may not enough. Therefore, if value is smaller than - * 20msec, this sets 20msec as timeout of DMA. + * See serial_core.c::uart_update_timeout(). + * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above + * function calculates 1 jiffie for the data plus 5 jiffies for the + * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA + * buffers (4 FIFO sizes), but when performing a faster transfer, the + * value obtained by this formula is too small. Therefore, if the value + * is smaller than 20ms, use 20ms as the timeout value for DMA. */ if (s->chan_rx) { unsigned int bits;