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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Kaehlcke Subject: Re: [PATCH v3 0/4] backlight: Expose brightness curve type through sysfs Date: Thu, 25 Jul 2019 10:17:26 -0700 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-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <20190725111541.GA23883@dell> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Lee Jones Cc: linux-pwm@vger.kernel.org, Daniel Thompson , Douglas Anderson , Bartlomiej Zolnierkiewicz , Jingoo Han , Brian Norris , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Thierry Reding , Jacek Anaszewski , Pavel Machek , Enric Balletbo i Serra List-Id: linux-pwm@vger.kernel.org T24gVGh1LCBKdWwgMjUsIDIwMTkgYXQgMTI6MTU6NDFQTSArMDEwMCwgTGVlIEpvbmVzIHdyb3Rl Ogo+IE9uIE1vbiwgMjIgSnVsIDIwMTksIE1hdHRoaWFzIEthZWhsY2tlIHdyb3RlOgo+IAo+ID4g T24gVHVlLCBKdWwgMDksIDIwMTkgYXQgMTI6MDA6MDNQTSAtMDcwMCwgTWF0dGhpYXMgS2FlaGxj a2Ugd3JvdGU6Cj4gPiA+IEJhY2tsaWdodCBicmlnaHRuZXNzIGN1cnZlcyBjYW4gaGF2ZSBkaWZm ZXJlbnQgc2hhcGVzLiBUaGUgdHdvIG1haW4KPiA+ID4gdHlwZXMgYXJlIGxpbmVhciBhbmQgbm9u LWxpbmVhciBjdXJ2ZXMuIFRoZSBodW1hbiBleWUgZG9lc24ndAo+ID4gPiBwZXJjZWl2ZSBsaW5l YXJseSBpbmNyZWFzaW5nL2RlY3JlYXNpbmcgYnJpZ2h0bmVzcyBhcyBsaW5lYXIgKHNlZQo+ID4g PiBhbHNvIDg4YmE5NWJlZGI3OSAiYmFja2xpZ2h0OiBwd21fYmw6IENvbXB1dGUgYnJpZ2h0bmVz cyBvZiBMRUQKPiA+ID4gbGluZWFybHkgdG8gaHVtYW4gZXllIiksIGhlbmNlIG1hbnkgYmFja2xp Z2h0cyB1c2Ugbm9uLWxpbmVhciAob2Z0ZW4KPiA+ID4gbG9nYXJpdGhtaWMpIGJyaWdodG5lc3Mg Y3VydmVzLiBUaGUgdHlwZSBvZiBjdXJ2ZSBpcyBjdXJyZW50bHkgb3BhcXVlCj4gPiA+IHRvIHVz ZXJzcGFjZSwgc28gdXNlcnNwYWNlIG9mdGVuIHJlbGllcyBvbiBtb3JlIG9yIGxlc3MgcmVsaWFi bGUKPiA+ID4gaGV1cmlzdGljcyAobGlrZSB0aGUgbnVtYmVyIG9mIGJyaWdodG5lc3MgbGV2ZWxz KSB0byBkZWNpZGUgd2hldGhlcgo+ID4gPiB0byB0cmVhdCBhIGJhY2tsaWdodCBkZXZpY2UgYXMg bGluZWFyIG9yIG5vbi1saW5lYXIuCj4gPiA+IAo+ID4gPiBFeHBvcnQgdGhlIHR5cGUgb2YgdGhl IGJyaWdodG5lc3MgY3VydmUgdmlhIGEgbmV3IHN5c2ZzIGF0dHJpYnV0ZS4KPiA+ID4gCj4gPiA+ IE1hdHRoaWFzIEthZWhsY2tlICg0KToKPiA+ID4gICBNQUlOVEFJTkVSUzogQWRkIGVudHJ5IGZv ciBzdGFibGUgYmFja2xpZ2h0IHN5c2ZzIEFCSSBkb2N1bWVudGF0aW9uCj4gPiA+ICAgYmFja2xp Z2h0OiBFeHBvc2UgYnJpZ2h0bmVzcyBjdXJ2ZSB0eXBlIHRocm91Z2ggc3lzZnMKPiA+ID4gICBi YWNrbGlnaHQ6IHB3bV9ibDogU2V0IHNjYWxlIHR5cGUgZm9yIENJRSAxOTMxIGN1cnZlcwo+ID4g PiAgIGJhY2tsaWdodDogcHdtX2JsOiBTZXQgc2NhbGUgdHlwZSBmb3IgYnJpZ2h0bmVzcyBjdXJ2 ZXMgc3BlY2lmaWVkIGluCj4gPiA+ICAgICB0aGUgRFQKPiA+ID4gCj4gPiA+ICAuLi4vQUJJL3Rl c3Rpbmcvc3lzZnMtY2xhc3MtYmFja2xpZ2h0ICAgICAgICAgfCAyNiArKysrKysrKysrKysrKwo+ ID4gPiAgTUFJTlRBSU5FUlMgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIHwgIDIg KysKPiA+ID4gIGRyaXZlcnMvdmlkZW8vYmFja2xpZ2h0L2JhY2tsaWdodC5jICAgICAgICAgICB8 IDE5ICsrKysrKysrKysKPiA+ID4gIGRyaXZlcnMvdmlkZW8vYmFja2xpZ2h0L3B3bV9ibC5jICAg ICAgICAgICAgICB8IDM1ICsrKysrKysrKysrKysrKysrKy0KPiA+ID4gIGluY2x1ZGUvbGludXgv YmFja2xpZ2h0LmggICAgICAgICAgICAgICAgICAgICB8ICA4ICsrKysrCj4gPiA+ICA1IGZpbGVz IGNoYW5nZWQsIDg5IGluc2VydGlvbnMoKyksIDEgZGVsZXRpb24oLSkKPiA+ID4gIGNyZWF0ZSBt b2RlIDEwMDY0NCBEb2N1bWVudGF0aW9uL0FCSS90ZXN0aW5nL3N5c2ZzLWNsYXNzLWJhY2tsaWdo dAo+ID4gCj4gPiBwaW5nLCBhbnkgY29tbWVudHMgb24gdjM/Cj4gCj4gTG9va3MgbGlrZSBQQVRD SCAyLzQgc3RpbGwgbmVlZHMgc2VlaW5nIHRvLgoKVGhlIHBhdGNoIGN1cnJlbnRseSBkb2Vzbid0 IGhhdmUgYW55IGNvbW1lbnRzLgoKRG8geW91IHNlZSBhbnkgc3BlY2lmaWMgdGhpbmdzIHRoYXQg bmVlZCBpbXByb3ZlbWVudD8gSWYgc28sIGNvdWxkIHlvdQpjb21tZW50IG9uIHRoZSBwYXRjaD8K ClRoYW5rcwoKTWF0dGhpYXMKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0 b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJp LWRldmVs From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Kaehlcke Date: Thu, 25 Jul 2019 17:17:26 +0000 Subject: Re: [PATCH v3 0/4] backlight: Expose brightness curve type through sysfs Message-Id: <20190725171726.GD250418@google.com> List-Id: References: <20190709190007.91260-1-mka@chromium.org> <20190722235926.GA250418@google.com> <20190725111541.GA23883@dell> In-Reply-To: <20190725111541.GA23883@dell> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Lee Jones Cc: linux-pwm@vger.kernel.org, Daniel Thompson , Douglas Anderson , Bartlomiej Zolnierkiewicz , Jingoo Han , Brian Norris , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Thierry Reding , Jacek Anaszewski , Pavel Machek , Enric Balletbo i Serra 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