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=-5.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 6BF94ECE58B for ; Sun, 6 Oct 2019 16:49:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 427F420862 for ; Sun, 6 Oct 2019 16:49:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="GCaLLOHA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726714AbfJFQsj (ORCPT ); Sun, 6 Oct 2019 12:48:39 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:44564 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725905AbfJFQsj (ORCPT ); Sun, 6 Oct 2019 12:48:39 -0400 Received: by mail-pl1-f193.google.com with SMTP id q15so5658271pll.11 for ; Sun, 06 Oct 2019 09:48:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:thread-topic:thread-index:date:message-id :references:in-reply-to:accept-language:content-language :content-transfer-encoding:mime-version; bh=TxLT9bpNl4jFVPAGhPpjPn1KDoP3vrxyC3V+3rCVHuM=; b=GCaLLOHABMVDzUOh3ZA+xjsSzoVnMe1OSpprvlXKbr3FidW133qVKYOkb5FIceNKPQ KHhGro4dl3fmL0QQgtMMhd1SRJuyWdL4b+DvJoTt3w+PgN2TNUg6wKYwvtQljvsSvTX+ a9JGo1FzYyiUJpewUjM7DGB6A/K63HuuJywazIzk6RwHxuUldu3Z7NftG8FGsWMjylMR QD7wgrgxUP2OrnU60tW2CAlbjcUtBPr5N3Op+7EcZrL4s0mcrzwJvlQuoSvl7TFaN1bS 411vNbPX7EZ9NkFNpKzsRMq5VLeHv+Vw77dlAZnGXIps6/nwZRNi/mO+jjHLTxt450TN ++BA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:thread-topic:thread-index :date:message-id:references:in-reply-to:accept-language :content-language:content-transfer-encoding:mime-version; bh=TxLT9bpNl4jFVPAGhPpjPn1KDoP3vrxyC3V+3rCVHuM=; b=jPif5b1bwPmIewJFp3OimaNzp7OgLaJKtFDrZgmgAiryA1t/dlcczC1dOPtN8nUfMl Kg4AAEp7BGb/4VE30F4D63Wce730T6w94m1TDgbsJtPgVHNeWt8iWJTEbCrg38kQPjCG rANuAWM7oktEgiMm7H1ZQp4/+NoYna7Zf2juvWe9AzBFIKHJAbkxkXU3cnV84cpoQRSD zb8vEdxQaWW0BPPIGKHr+KZuQyks5A2cWLtpo4CMqIhJaxjCJXZZrG7W9Ob4Jz081RLN Olq5bm3BNnZU9Cqhh0KjAcMeADDh4Wh3+BVA14U8vPLh6SWlnM+Hkgz8FYxyaDxi8vVZ VHcw== X-Gm-Message-State: APjAAAV9UM8jBOK3mehqHCYU/d8OSqa+qAiihsaEsi1lo2G2dBb4Vza8 Mws7ib1Y8N2kHlQ4K+JZo3o= X-Google-Smtp-Source: APXvYqzmjl+mcprCJRZxez82R7Yc8QkQNXYtyYVkQIbk7eqcboNITANQlLm+Tif+J1GnDnyYzSmYPg== X-Received: by 2002:a17:902:563:: with SMTP id 90mr24478184plf.13.1570380518616; Sun, 06 Oct 2019 09:48:38 -0700 (PDT) Received: from SL2P216MB0105.KORP216.PROD.OUTLOOK.COM ([2603:1046:100:22::5]) by smtp.gmail.com with ESMTPSA id h2sm20378814pfq.108.2019.10.06.09.48.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 06 Oct 2019 09:48:37 -0700 (PDT) From: Jingoo Han To: Pavel Machek , Daniel Thompson , "alex@alexanderweb.de" , "andriy.shevchenko@linux.intel.com" CC: Jani Nikula , Jonathan Corbet , Mat King , "rafael@kernel.org" , "gregkh@linuxfoundation.org" , Ross Zwisler , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , Rajat Jain , Lee Jones , Alexander Schremmer , Andy Shevchenko , Han Jingoo Subject: Re: New sysfs interface for privacy screens Thread-Topic: New sysfs interface for privacy screens Thread-Index: AXdoTmVTBb+NyICdEDRjYqdq56nWEjUwLjQwZmZpcml2Y2w1MDUyNTEwse7NLzw= X-MS-Exchange-MessageSentRepresentingType: 1 Date: Sun, 6 Oct 2019 16:48:31 +0000 Message-ID: References: <20191002094650.3fc06a85@lwn.net> <87muei9r7i.fsf@intel.com> <20191003102254.dmwl6qimdca3dbrv@holly.lan> <20191006110455.GC24605@amd> In-Reply-To: <20191006110455.GC24605@amd> Accept-Language: ko-KR, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-Exchange-Organization-SCL: -1 X-MS-TNEF-Correlator: X-MS-Exchange-Organization-RecordReviewCfmType: 0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On 10/6/19, 7:04 AM, Pavel Machek wrote: > > Hi! > > > > >> I have been looking into adding Linux support for electronic priva= cy > > > >> screens which is a feature on some new laptops which is built into= the > > > >> display and allows users to turn it on instead of needing to use a > > > >> physical privacy filter. In discussions with my colleagues the ide= a of > > > >> using either /sys/class/backlight or /sys/class/leds but this new > > > >> feature does not seem to quite fit into either of those classes. > > > > > > > > FWIW, it seems that you're not alone in this; 5.4 got some support = for > > > > such screens if I understand things correctly: > > > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.gi= t/commit/?id=3D110ea1d833ad > > >=20 > > > Oh, I didn't realize it got merged already, I thought this was > > > related... > > >=20 > > > So we've already replicated the backlight sysfs interface problem for > > > privacy screens. :( > >=20 > > I guess... although the Thinkpad code hasn't added any standard > > interfaces (no other laptop should be placing controls for a privacy > > screen in /proc/acpi/ibm/... ). Maybe its not too late. > > There's new interface for controlling privacyguard... but perhaps we > need better solution than what went in 5.4. Perhaps it should be > reconsidered? I agree with your opinion. I also think that better solution can be conside= red, although there is already something in 5.4. Best regards, Jingoo Han > > Best regards, > Pavel > --=20 > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/b= log.html