From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1517815557; cv=none; d=google.com; s=arc-20160816; b=AS0Jj0M7SU+otHeuPIawZGqCewAxZ3nGW91qz5pjWyufGmdSzIGbM+HVq4IHTBeLUs DMAgpfk+KPETP9561zy5Di888OtOmLGeANYk3MO8Rh8n2zKVVJFBoWTklpzi6NuAd74+ 4WA0yVd7L3AtONNz9XrjZGR9eCJ7ghUYI7xod06V3PBC8ZKPuxcx1VRUPLdR+7RGZxqh 1J/57Z5Cu21SJ8h4vEp5fqiQ4kKP3ygTaLoyBrxo7SD2icuMeaJudpJ0AECAtJG1KGV8 /TxGWyeHYvEhVkdaPSFfN7ikxeItfDzHV8BNY91ZQvflsPqfrmacx42btYq5ku0F+w/Q RTqA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:dkim-signature :arc-authentication-results; bh=z9jrVL0TPR14YaeZJwdyamryRmx+cp2X6g9rxoa/F88=; b=jAsVcZJWGHvKdzw3qN+srwTfV52eBf3a0o91g39MFVaaGMWq0TG3qjrEAkz6hCkre3 ewIdPOUqvwycmr5EXP1Rk5eKZY+WJGOS988gY5B5uOfy/XRS/GLRl9Dcka5mIacGCQ9a OEUZwjtlnKmGTMDGuVe+rZf2tha7Vx7kuD3FFBSvdNO3zeDgJ+B9RIbqg383gMiYVkLe s+50ypkF1RRGfGpoSsTK6tEmGmPBQzPuHkzDYTAC3U3ZmaRonN4cJrRvU107rTOUM7aY welAvatWvstCpqazigsfRdrqlSnYlZKmt4mnfODhnDVd6IBBvYlqI+kqngciy0jDu4qx Ybkg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=WFyIQ9kc; spf=pass (google.com: domain of aishpant@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=aishpant@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=WFyIQ9kc; spf=pass (google.com: domain of aishpant@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=aishpant@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gmail.com X-Google-Smtp-Source: AH8x224oGhm6B6rILbDKFJDl3Xcot5FKgmlTfVQ6JEcEqDMz4JZ6VtkHEaOgVE3AHsehVcbMu4BoPQ== Date: Mon, 5 Feb 2018 12:55:50 +0530 From: Aishwarya Pant To: Daniel Thompson Cc: Jani Nikula , Milo Kim , linux-fbdev@vger.kernel.org, Bartlomiej Zolnierkiewicz , Jingoo Han , Jonathan Corbet , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Julia Lawall , Greg KH , Lee Jones Subject: Re: [PATCH 1/5] backlight: lp8788: document sysfs attributes Message-ID: <20180205072550.GA9376@mordor.localdomain> References: <6523e26889d3dd65e90ea27c0d302a95aeb9da8b.1516978005.git.aishpant@gmail.com> <20180131110727.rmmwyqzwozwhda6z@oak.lan> <878tceckli.fsf@intel.com> <20180201113604.kcue6auuivud52qz@oak.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180201113604.kcue6auuivud52qz@oak.lan> User-Agent: Mutt/1.9.3 (2018-01-21) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590666949916676069?= X-GMAIL-MSGID: =?utf-8?q?1591544966340498933?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Thu, Feb 01, 2018 at 11:36:04AM +0000, Daniel Thompson wrote: > On Wed, Jan 31, 2018 at 01:51:21PM +0200, Jani Nikula wrote: > > On Wed, 31 Jan 2018, Daniel Thompson wrote: > > > On Fri, Jan 26, 2018 at 08:20:08PM +0530, Aishwarya Pant wrote: > > >> Add documentation for sysfs interfaces of lp8788 backlight driver by > > >> looking through the code and the git commit history. > > >> > > >> Signed-off-by: Aishwarya Pant > > >> --- > > >> Documentation/ABI/testing/sysfs-class-backlight-lp8788 | 10 ++++++++++ > > >> 1 file changed, 10 insertions(+) > > >> create mode 100644 Documentation/ABI/testing/sysfs-class-backlight-lp8788 > > >> > > >> diff --git a/Documentation/ABI/testing/sysfs-class-backlight-lp8788 b/Documentation/ABI/testing/sysfs-class-backlight-lp8788 > > >> new file mode 100644 > > >> index 000000000000..c0e565c8d63d > > >> --- /dev/null > > >> +++ b/Documentation/ABI/testing/sysfs-class-backlight-lp8788 > > >> @@ -0,0 +1,10 @@ > > >> +sysfs interface for Texas Instruments lp8788 mfd backlight driver > > >> +----------------------------------------------------------------- > > >> + > > >> +What: /sys/class/backlight//bl_ctl_mode > > >> +Date: Feb, 2013 > > >> +KernelVersion: v3.10 > > >> +Contact: Milo Kim > > >> +Description: > > >> + (RO) Displays whether the brightness is controlled by the PWM > > >> + input("PWM based") or the I2C register("Register based"). > > > > > > I rather dislike drivers with this type of "bonus" sysfs controls. I'm > > > struggling to come up with any reason why the userspace would want to > > > read this control (and I think bl_ctl_mode gets the fewest hits after > > > searching with google hits of any search I've tried) . It looks to me > > > like this is debug information that should never have gone into sysfs > > > at all. > > > > Agreed. I think the same holds for the other extra sysfs attributes. At > > worst, having these prevents the backlight class from adding the names > > later on, which is just backwards. > > The problem is that they do exist... > > For controls which appear to be misplaced debug attributes I think I am > happy to nuke the values entirely. It is extremely improbable that any > userspace will notice. > > Unfortunately some of the controls look like they could be poked by an > custom userspace so I'm quite so confident about nuking these ones...and if we > don't nuke we should document (so thanks Aishwarya!). > Hi Thanks for reviewing. Should I take it to assume that we would like to keep the debug-like attributes in documentation for now? Aishwarya > > Daniel.