From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752102AbbIID70 (ORCPT ); Tue, 8 Sep 2015 23:59:26 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60565 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752829AbbIID7R (ORCPT ); Tue, 8 Sep 2015 23:59:17 -0400 Date: Tue, 8 Sep 2015 20:58:50 -0700 From: Greg KH To: Guenter Roeck Cc: Emilio =?iso-8859-1?Q?L=F3pez?= , olof@lixom.net, kgene@kernel.org, k.kozlowski@samsung.com, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org Subject: Re: [PATCH 1/3] sysfs: Fix is_visible() support for binary attributes Message-ID: <20150909035850.GA5497@kroah.com> References: <1441714066-5599-1-git-send-email-emilio.lopez@collabora.co.uk> <1441714066-5599-2-git-send-email-emilio.lopez@collabora.co.uk> <20150908153013.GA6758@roeck-us.net> <20150908191002.GB10156@kroah.com> <20150908193052.GA11106@roeck-us.net> <55EF82A4.5000502@collabora.co.uk> <55EF86F8.3060406@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <55EF86F8.3060406@roeck-us.net> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 08, 2015 at 06:10:16PM -0700, Guenter Roeck wrote: > Hi Emilio, > > On 09/08/2015 05:51 PM, Emilio López wrote: > >Hi Greg & Guenter, > > > [ ... ] > >>>> > >>>>Unless I am missing something, this is not explained anywhere, but it is > >>>>not entirely trivial to understand. I think it should be documented. > > > >I agree. I couldn't find any mention of what this int was supposed to be by looking at Documentation/ (is_visible is not even mentioned :/) or include/linux/sysfs.h. Once we settle on something I'll document it before sending a v2. > > > In the include file ? No strong preference, though. > > >By the way, I wrote a quick coccinelle script to match is_visible() users which reference the index (included below), and it found references to drivers which do not seem to use any binary attributes, so I believe changing the index meaning shouldn't be an issue. > > > Good. > > >>>I agree, make i the number of the bin attribute and that should solve > >>>this issue. > >>> > >>No, that would conflict with the "normal" use of is_visible for non-binary > >>attributes, and make the index all but useless, since the is_visible function > >>would have to search through all the attributes anyway to figure out which one > >>is being checked. > > > >Yeah, using the same indexes would be somewhat pointless, although not many seem to be using it anyway (only 14 files matched). Others seem to be comparing the attr* instead. An alternative would be to use negative indexes for binary attributes and positive indexes for normal attributes. > > > ... and I probably wrote or reviewed a significant percentage of those ;-). > > Using negative numbers for binary attributes is an interesting idea. > Kind of unusual, though. Greg, any thoughts on that ? Ick, no, that's a mess, maybe we just could drop the index alltogether? thanks, greg k-h