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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 2F32FC07E85 for ; Sun, 9 Dec 2018 22:12:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECEE6208E7 for ; Sun, 9 Dec 2018 22:12:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECEE6208E7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728304AbeLIWMG (ORCPT ); Sun, 9 Dec 2018 17:12:06 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:37764 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727647AbeLIWME (ORCPT ); Sun, 9 Dec 2018 17:12:04 -0500 Received: from pub.yeoldevic.com ([81.174.156.145] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gW73R-0002ie-2W; Sun, 09 Dec 2018 21:56:01 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gW72Z-0003FJ-Du; Sun, 09 Dec 2018 21:55:07 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Greg Kroah-Hartman" , "Johan Hovold" Date: Sun, 09 Dec 2018 21:50:33 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 040/328] tty: fix termios input-speed encoding when using BOTHER In-Reply-To: X-SA-Exim-Connect-IP: 81.174.156.145 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.62-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 1cee38f0363a88db374e50b232ca17b9a4c12fa0 upstream. When the termios CIBAUD bits are left unset (i.e. B0), we use the same output and input speed and should leave CIBAUD unchanged. When the user requests a rate using BOTHER and c_ospeed which the driver cannot set exactly, the driver can report back the actual baud rate using tty_termios_encode_baud_rate(). If this rate is close enough to a standard rate however, we could end up setting CIBAUD to a Bfoo value despite the user having left it unset. This in turn could lead to an unexpected input rate being set on subsequent termios updates. Fix this by using a zero tolerance value also for the input rate when CIBAUD is clear so that the matching logic works as expected. Fixes: 78137e3b34e1 ("[PATCH] tty: improve encode_baud_rate logic") Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings --- drivers/tty/tty_ioctl.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -407,16 +407,20 @@ void tty_termios_encode_baud_rate(struct termios->c_ospeed = obaud; #ifdef BOTHER + if ((termios->c_cflag >> IBSHIFT) & CBAUD) + ibinput = 1; /* An input speed was specified */ + /* If the user asked for a precise weird speed give a precise weird answer. If they asked for a Bfoo speed they may have problems digesting non-exact replies so fuzz a bit */ - if ((termios->c_cflag & CBAUD) == BOTHER) + if ((termios->c_cflag & CBAUD) == BOTHER) { oclose = 0; + if (!ibinput) + iclose = 0; + } if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER) iclose = 0; - if ((termios->c_cflag >> IBSHIFT) & CBAUD) - ibinput = 1; /* An input speed was specified */ #endif termios->c_cflag &= ~CBAUD; #ifdef IBSHIFT