From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailout2.w1.samsung.com ([210.118.77.12]:8604 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754525AbbBTQPO (ORCPT ); Fri, 20 Feb 2015 11:15:14 -0500 Message-id: <54E75D8E.40004@samsung.com> Date: Fri, 20 Feb 2015 17:15:10 +0100 From: Jacek Anaszewski MIME-version: 1.0 To: Greg KH Cc: Sakari Ailus , Pavel Machek , linux-leds@vger.kernel.org, linux-media@vger.kernel.org, devicetree@vger.kernel.org, kyungmin.park@samsung.com, cooloney@gmail.com, rpurdie@rpsys.net, s.nawrocki@samsung.com Subject: Re: 0.led_name 2.other.led.name in /sysfs Re: [PATCH/RFC v11 01/20] leds: flash: document sysfs interface References: <1424276441-3969-1-git-send-email-j.anaszewski@samsung.com> <1424276441-3969-2-git-send-email-j.anaszewski@samsung.com> <20150218224747.GA3999@amd> <20150219090204.GI3915@valkosipuli.retiisi.org.uk> <20150219214043.GB29875@kroah.com> <54E6E89B.4050404@samsung.com> <20150220153616.GB18111@kroah.com> In-reply-to: <20150220153616.GB18111@kroah.com> Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 02/20/2015 04:36 PM, Greg KH wrote: > On Fri, Feb 20, 2015 at 08:56:11AM +0100, Jacek Anaszewski wrote: >> On 02/19/2015 10:40 PM, Greg KH wrote: >>> On Thu, Feb 19, 2015 at 11:02:04AM +0200, Sakari Ailus wrote: >>>> On Wed, Feb 18, 2015 at 11:47:47PM +0100, Pavel Machek wrote: >>>>> >>>>> On Wed 2015-02-18 17:20:22, Jacek Anaszewski wrote: >>>>>> Add a documentation of LED Flash class specific sysfs attributes. >>>>>> >>>>>> Signed-off-by: Jacek Anaszewski >>>>>> Acked-by: Kyungmin Park >>>>>> Cc: Bryan Wu >>>>>> Cc: Richard Purdie >>>>> >>>>> NAK-ed-by: Pavel Machek >>>>> >>>>>> +What: /sys/class/leds//available_sync_leds >>>>>> +Date: February 2015 >>>>>> +KernelVersion: 3.20 >>>>>> +Contact: Jacek Anaszewski >>>>>> +Description: read/write >>>>>> + Space separated list of LEDs available for flash strobe >>>>>> + synchronization, displayed in the format: >>>>>> + >>>>>> + led1_id.led1_name led2_id.led2_name led3_id.led3_name etc. >>>>> >>>>> Multiple values per file, with all the problems we had in /proc. I >>>>> assume led_id is an integer? What prevents space or dot in led name? >>>> >>>> Very good point. How about using a newline instead? That'd be a little bit >>>> easier to parse, too. >>> >>> No, please make it one value per-file, which is what sysfs requires. >> >> The purpose of this attribute is only to provide an information about >> the range of valid identifiers that can be written to the >> flash_sync_strobe attribute. Wouldn't splitting this to many attributes >> be an unnecessary inflation of sysfs files? > > Ok a list of allowed values to write is acceptable, as long as it is not > hard to parse and always is space separated. Is a new line character also acceptable as a delimiter? >> Apart from it, we have also flash_faults attribute, that currently >> provides a space separated list of flash faults that have occurred. > > That's crazy, what's to keep it from growing and growing to be larger > than is allowed to be read? The number of possible faults is fixed to 9 currently. They are presented in the form of strings no longer currently than 40 characters. There can be maximum 9 faults reported at a time, this is not a kind of a log. This will allow to define roughly 100 types of faults, having that PAGE_SIZE is 4096. I think this is far more than it is conceivable for the simple LED flash device. >> If we are to stick tightly to the one-value-per-file rule, then how >> we should approach flash_faults case? Should the separate file be >> dynamically created for each reported fault? > > I think you need to use something other than sysfs here, sorry. > > uevents for your faults? > > thanks, > > greg k-h > -- Best Regards, Jacek Anaszewski