From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751848AbbEFTJm (ORCPT ); Wed, 6 May 2015 15:09:42 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:52298 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751496AbbEFTJi (ORCPT ); Wed, 6 May 2015 15:09:38 -0400 Date: Wed, 6 May 2015 21:09:22 +0200 From: Greg KH To: nick Cc: Ian Abbott , hsweeten@visionengravers.com, chase.southwood@gmail.com, ebru.akagunduz@gmail.com, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: Question about the function,ni_stc_dma_channel_select_bitfield Message-ID: <20150506190922.GA10511@kroah.com> References: <55495EA8.2090902@gmail.com> <5549DA9B.6030700@mev.co.uk> <554A1FC3.3000409@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <554A1FC3.3000409@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 06, 2015 at 10:05:55AM -0400, nick wrote: > On 2015-05-06 05:10 AM, Ian Abbott wrote: > > On 06/05/15 01:22, nick wrote: > >> Greetings All, > >> I am wondering if in the function,ni_stc_dma_channel_select_bitfield the line: > >> return 1 << channel; > >> is guaranteed to be below the threshold that guarantees us to not overflow on > >> a unsigned 32 integer due to bit wise shifting to the left. > >> Thanks Nick > >> > > > > if (channel < 4) > > return 1 << channel; > > > > So, yes. > > > This should be commented in my option as this is not common knowledge > unless you known the hardware specs really well. If I should send in > a patch adding a comment here please let me known. Nick, this is one reason why you were banned from all vger.kernel.org mailing lists. You are wasting people's time and refuse to listen to others. I do give you credit for coming up with very strange questions that show a complete lack of understanding of the C language, that is intertaining at times, like this response, nice job with that. Please everyone, just add him to your killfile and ignore him, it makes life much easier these days when he tries to go around the vger ban by emailing developers directly as he did here. greg k-h