From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH 1/3] sysfs: Fix is_visible() support for binary attributes Date: Tue, 08 Sep 2015 21:12:37 -0700 Message-ID: <55EFB1B5.1060703@roeck-us.net> 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> <20150909035850.GA5497@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:56260 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750720AbbIIEMn (ORCPT ); Wed, 9 Sep 2015 00:12:43 -0400 In-Reply-To: <20150909035850.GA5497@kroah.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Greg KH Cc: =?windows-1252?Q?Emilio_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 On 09/08/2015 08:58 PM, Greg KH wrote: > On Tue, Sep 08, 2015 at 06:10:16PM -0700, Guenter Roeck wrote: >> Hi Emilio, >> >> On 09/08/2015 05:51 PM, Emilio L=F3pez wrote: >>> Hi Greg & Guenter, >>> >> [ ... ] >>>>>> >>>>>> Unless I am missing something, this is not explained anywhere, b= ut it is >>>>>> not entirely trivial to understand. I think it should be documen= ted. >>> >>> 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 i= t 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 referen= ces to drivers which do not seem to use any binary attributes, so I bel= ieve changing the index meaning shouldn't be an issue. >>> >> Good. >> >>>>> I agree, make i the number of the bin attribute and that should s= olve >>>>> this issue. >>>>> >>>> No, that would conflict with the "normal" use of is_visible for no= n-binary >>>> attributes, and make the index all but useless, since the is_visib= le function >>>> would have to search through all the attributes anyway to figure o= ut 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 see= m to be comparing the attr* instead. An alternative would be to use neg= ative indexes for binary attributes and positive indexes for normal att= ributes. >>> >> ... and I probably wrote or reviewed a significant percentage of tho= se ;-). >> >> 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 alltogethe= r? > No, please don't. Having to manually compare dozens of index pointers w= ould be even more of a mess. Guenter From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@roeck-us.net (Guenter Roeck) Date: Tue, 08 Sep 2015 21:12:37 -0700 Subject: [PATCH 1/3] sysfs: Fix is_visible() support for binary attributes In-Reply-To: <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> <20150909035850.GA5497@kroah.com> Message-ID: <55EFB1B5.1060703@roeck-us.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 09/08/2015 08:58 PM, Greg KH wrote: > On Tue, Sep 08, 2015 at 06:10:16PM -0700, Guenter Roeck wrote: >> Hi Emilio, >> >> On 09/08/2015 05:51 PM, Emilio L?pez 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? > No, please don't. Having to manually compare dozens of index pointers would be even more of a mess. Guenter