Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753291AbaGKKNj (ORCPT ); Fri, 11 Jul 2014 06:13:39 -0400 Received: from mail-la0-f49.google.com ([209.85.215.49]:42209 "EHLO mail-la0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751760AbaGKKNh (ORCPT ); Fri, 11 Jul 2014 06:13:37 -0400 From: Andrey Utkin To: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, devel@driverdev.osuosl.org Cc: gregkh@linuxfoundation.org, hsweeten@visionengravers.com, abbotti@mev.co.uk, dcb314@hotmail.com, Andrey Utkin Subject: [PATCH] drivers/staging/comedi/drivers/ni_atmio16d.c: remove pointless condition Date: Fri, 11 Jul 2014 13:13:23 +0300 Message-Id: <1405073603-21468-1-git-send-email-andrey.krieger.utkin@gmail.com> X-Mailer: git-send-email 1.8.3.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The issue was discovered with static analysis and has two instances in this file. The code looks like this if (x < 65536000) { ... } else if (x < 655360000) { ... } else if (x <= 0xffffffff /* 6553600000 */) { ... } else if (x <= 0xffffffff /* 65536000000 */) { ... } The meaning of this block is to select appropriate clock frequency for interval timer basing on "x", which is amount of time. Notes: 1. That last condition matches previous one - that's the issue. 2. Decimal numbers in comments don't match hex numbers in expressions. But in first case the numbers have same order, while in the second case the hex number is the same, and the decimal one is 10 times bigger. 3. Actually type of "x" is "unsigned int", so its exact upper limit is not obviously known. 4. There's no "else" block. So it makes sense to make an "else" block from last "else if" case. The code inside the block seems correct for such usage. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=79871 Reported-by: David Binderman Signed-off-by: Andrey Utkin --- drivers/staging/comedi/drivers/ni_atmio16d.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_atmio16d.c b/drivers/staging/comedi/drivers/ni_atmio16d.c index 6ad27f5..895b56d 100644 --- a/drivers/staging/comedi/drivers/ni_atmio16d.c +++ b/drivers/staging/comedi/drivers/ni_atmio16d.c @@ -338,7 +338,7 @@ static int atmio16d_ai_cmd(struct comedi_device *dev, } else if (cmd->convert_arg <= 0xffffffff /* 6553600000 */) { base_clock = CLOCK_10_KHZ; timer = cmd->convert_arg / 100000; - } else if (cmd->convert_arg <= 0xffffffff /* 65536000000 */) { + } else { base_clock = CLOCK_1_KHZ; timer = cmd->convert_arg / 1000000; } @@ -406,7 +406,7 @@ static int atmio16d_ai_cmd(struct comedi_device *dev, } else if (cmd->scan_begin_arg < 0xffffffff /* 6553600000 */) { base_clock = CLOCK_10_KHZ; timer = cmd->scan_begin_arg / 100000; - } else if (cmd->scan_begin_arg < 0xffffffff /* 65536000000 */) { + } else { base_clock = CLOCK_1_KHZ; timer = cmd->scan_begin_arg / 1000000; } -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/