From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CEF24C7618B for ; Thu, 25 Jul 2019 17:17:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95CE72238C for ; Thu, 25 Jul 2019 17:17:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Gzmt01iV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726283AbfGYRRb (ORCPT ); Thu, 25 Jul 2019 13:17:31 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:43641 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725878AbfGYRRa (ORCPT ); Thu, 25 Jul 2019 13:17:30 -0400 Received: by mail-pl1-f194.google.com with SMTP id 4so16671048pld.10 for ; Thu, 25 Jul 2019 10:17:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=tPVqVnzmvlRxnAy1nlx0FuoHgdEqnAev2P/iqrvyRAA=; b=Gzmt01iVIH1Bred1XXVjQaOCqWazRRFK9XDsc7huxBWzN5+Wk20p62OgxhtyDEfCjH m4OjvYBjArWhuK+l4JVeBEcLcy1ACe9AyZBHhkrE8Zw9EbZjPhD/aFMWJQCRguVdoNfj Y2/KhTuUR487XJzbutf1bxfnR2xCz1ZysJxLs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=tPVqVnzmvlRxnAy1nlx0FuoHgdEqnAev2P/iqrvyRAA=; b=I2c4+Of45Aww5M5EDsoxhC5laUf0xfMel7gAcfnBDNWkiKRX4fSMjw4unS37AcRMmm N0F7BmxVt0JcbG/jUM4FwAyJkzjS6m9iAFHcpPvMKeyWxSpSdfKn1j1PtP86TI/XJ8bo 4oDC7bEDF1gmyCSzOKHyXOHqwGlR759p5n9JFsW8MLwthalZkIE1dLTdCQhe6NaboTnW OScd1OvRcr+nqTTfGEnosMKU3Z8WAh3KBFpUH9RhMq+wXvHFTcsWBjfGFWba+Gu3eTXN +TwLe39GOsWP7ivYZ5MzSMJD8Nd2FVEuqI+eFlYsmxvXWS9VWZ09PqPYODit4snGDpzL 0nfQ== X-Gm-Message-State: APjAAAUAZLbsErYEmabwMR2OpIRlhFUPjeu02ACTeT3acak8Svz1DcbG ipFUh77eHu6MhsDHGM3ZY2+U8g== X-Google-Smtp-Source: APXvYqws5odlydH4ebEFOkZgM8ILSO3F0QORLUvSUh4M4JwkPcu4YkyXn+XUbv1ErfBXv358RQkmHg== X-Received: by 2002:a17:902:934a:: with SMTP id g10mr93724757plp.18.1564075050259; Thu, 25 Jul 2019 10:17:30 -0700 (PDT) Received: from localhost ([2620:15c:202:1:75a:3f6e:21d:9374]) by smtp.gmail.com with ESMTPSA id q126sm6606292pfb.56.2019.07.25.10.17.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Jul 2019 10:17:28 -0700 (PDT) Date: Thu, 25 Jul 2019 10:17:26 -0700 From: Matthias Kaehlcke To: Lee Jones Cc: Thierry Reding , Daniel Thompson , Jingoo Han , Bartlomiej Zolnierkiewicz , linux-pwm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Enric Balletbo i Serra , Douglas Anderson , Brian Norris , Pavel Machek , Jacek Anaszewski Subject: Re: [PATCH v3 0/4] backlight: Expose brightness curve type through sysfs Message-ID: <20190725171726.GD250418@google.com> References: <20190709190007.91260-1-mka@chromium.org> <20190722235926.GA250418@google.com> <20190725111541.GA23883@dell> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190725111541.GA23883@dell> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 25, 2019 at 12:15:41PM +0100, Lee Jones wrote: > On Mon, 22 Jul 2019, Matthias Kaehlcke wrote: > > > On Tue, Jul 09, 2019 at 12:00:03PM -0700, Matthias Kaehlcke wrote: > > > Backlight brightness curves can have different shapes. The two main > > > types are linear and non-linear curves. The human eye doesn't > > > perceive linearly increasing/decreasing brightness as linear (see > > > also 88ba95bedb79 "backlight: pwm_bl: Compute brightness of LED > > > linearly to human eye"), hence many backlights use non-linear (often > > > logarithmic) brightness curves. The type of curve is currently opaque > > > to userspace, so userspace often relies on more or less reliable > > > heuristics (like the number of brightness levels) to decide whether > > > to treat a backlight device as linear or non-linear. > > > > > > Export the type of the brightness curve via a new sysfs attribute. > > > > > > Matthias Kaehlcke (4): > > > MAINTAINERS: Add entry for stable backlight sysfs ABI documentation > > > backlight: Expose brightness curve type through sysfs > > > backlight: pwm_bl: Set scale type for CIE 1931 curves > > > backlight: pwm_bl: Set scale type for brightness curves specified in > > > the DT > > > > > > .../ABI/testing/sysfs-class-backlight | 26 ++++++++++++++ > > > MAINTAINERS | 2 ++ > > > drivers/video/backlight/backlight.c | 19 ++++++++++ > > > drivers/video/backlight/pwm_bl.c | 35 ++++++++++++++++++- > > > include/linux/backlight.h | 8 +++++ > > > 5 files changed, 89 insertions(+), 1 deletion(-) > > > create mode 100644 Documentation/ABI/testing/sysfs-class-backlight > > > > ping, any comments on v3? > > Looks like PATCH 2/4 still needs seeing to. The patch currently doesn't have any comments. Do you see any specific things that need improvement? If so, could you comment on the patch? Thanks Matthias