From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailout1.w1.samsung.com ([210.118.77.11]:19926 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753852AbaLAN7A (ORCPT ); Mon, 1 Dec 2014 08:59:00 -0500 Message-id: <547C7420.4080801@samsung.com> Date: Mon, 01 Dec 2014 14:58:56 +0100 From: Jacek Anaszewski MIME-version: 1.0 To: Pavel Machek Cc: linux-leds@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, kyungmin.park@samsung.com, b.zolnierkie@samsung.com, cooloney@gmail.com, rpurdie@rpsys.net, sakari.ailus@iki.fi, s.nawrocki@samsung.com Subject: Re: [PATCH/RFC v8 02/14] Documentation: leds: Add description of LED Flash class extension References: <1417166286-27685-1-git-send-email-j.anaszewski@samsung.com> <1417166286-27685-3-git-send-email-j.anaszewski@samsung.com> <20141129125832.GA315@amd> <547C539A.4010500@samsung.com> <20141201130437.GB24737@amd> In-reply-to: <20141201130437.GB24737@amd> Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Pavel, On 12/01/2014 02:04 PM, Pavel Machek wrote: > Hi! > >>> How are faults cleared? Should it be list of strings, instead of >>> bitmask? We may want to add new fault modes in future... >> >> Faults are cleared by reading the attribute. I will add this note. >> There can be more than one fault at a time. I think that the bitmask >> is a flexible solution. I don't see any troubles related to adding >> new fault modes in the future, do you? > > I do not think that "read attribute to clear" is good idea. Normally, > you'd want the error attribute world-readable, but you don't want > non-root users to clear the errors. This is also V4L2_CID_FLASH_FAULT control semantics. Moreover many devices clear the errors upon reading register. I don't see anything wrong in the fact that an user can clear an error. If the user has a permission to use a device then it also should be allowed to clear the errors. > I am not sure if bitmask is good solution. I'd return space-separated > strings like "overtemp". That way, there's good chance that other LED > drivers would be able to use similar interface... The format of a sysfs attribute should be concise. The error codes are generic and map directly to the V4L2 Flash error codes. Best Regards, Jacek Anaszewski