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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 174E0C67871 for ; Thu, 27 Oct 2022 10:38:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A1ADE10E38C; Thu, 27 Oct 2022 10:37:58 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id B96D610E5C8 for ; Thu, 27 Oct 2022 10:37:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666867073; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KIrIm83XlmkQEHvLgMNI62dGgv/hpRuvnAfiEarWzlw=; b=OHGWG0YHNBiMFKLKAcQDT1KtbGf2FrcBxY2yfsk9zKclprYVL0Vfvq/QNHGLS5SUWjpqaR Mi7znTXIfahKwOx7HysHLQ6C7RGV716ZCCT0K207WRKHQneP+NWtiuYDXEd3uJGAdLyTiR 8M97wGP51arPMxcQ+uJQIN7IpQWcWo8= Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-312-Zn_kaVQlNIi16bz2Pg500w-1; Thu, 27 Oct 2022 06:37:52 -0400 X-MC-Unique: Zn_kaVQlNIi16bz2Pg500w-1 Received: by mail-ed1-f71.google.com with SMTP id e15-20020a056402190f00b00461b0576620so833377edz.2 for ; Thu, 27 Oct 2022 03:37:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=KIrIm83XlmkQEHvLgMNI62dGgv/hpRuvnAfiEarWzlw=; b=NJeK8YWU6Rjw8sJAzbAiqQNmtpMlBiC6C1Xx/sSz1BlzNSzFZKjJrAE4MRgHTTOYOY vLMNkzLd1lVb3pYRNi77lcjntSmZNGCvnYNI3+vd5acWwWgRvek0QOe8k3SoAoHStq0h DzXV/7o9T3krAvCKvAlbhoZIFTQ+tAKvxcTRjazwHkIqVO2PrBSqV8Hayl5O5jDfJP1m ySmN9gk6sNw/Spc1C5HwqyVyStfDkXNpB3nlE2BXiQarCg5Pocq6AIyfhAm+slh09tp7 EgQI2a/kS51+JAsz3ri1MBEtX/sFNnS7LDtuyXufPOBFQDMrHwHGHBg+j4+x8IVyU4Li 8nwA== X-Gm-Message-State: ACrzQf0XxHnxNKucvLSgnY1Wx8PH4Qwmpx6EIhOBVHpRfaU7ks4tAGQC lnqJcIBx+ccR9LGD6T0PxAQVp14dj+t/pQc0vp6LGDHg0gwO6Ytg4KKdqEwRvfBjyQWeepF5pDh W73a2HcY3/pFpUlyQMKAzv2Wxlw== X-Received: by 2002:a17:906:9bd8:b0:78d:85f9:36ae with SMTP id de24-20020a1709069bd800b0078d85f936aemr42186646ejc.342.1666867071311; Thu, 27 Oct 2022 03:37:51 -0700 (PDT) X-Google-Smtp-Source: AMsMyM5SZMU3P4Zsb6VMxou+01MOar68Mbr9wEuDuf/meiI+Zmby9PhRAPjCmSxwGQr42Uzv+ipmOg== X-Received: by 2002:a17:906:9bd8:b0:78d:85f9:36ae with SMTP id de24-20020a1709069bd800b0078d85f936aemr42186603ejc.342.1666867071054; Thu, 27 Oct 2022 03:37:51 -0700 (PDT) Received: from ?IPV6:2001:1c00:c1e:bf00:d69d:5353:dba5:ee81? (2001-1c00-0c1e-bf00-d69d-5353-dba5-ee81.cable.dynamic.v6.ziggo.nl. [2001:1c00:c1e:bf00:d69d:5353:dba5:ee81]) by smtp.gmail.com with ESMTPSA id i14-20020a50c3ce000000b004587c2b5048sm739068edf.52.2022.10.27.03.37.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 27 Oct 2022 03:37:50 -0700 (PDT) Message-ID: <6df2016d-ed2d-57fa-dcad-48537732895f@redhat.com> Date: Thu, 27 Oct 2022 12:37:49 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.1 To: Matthew Garrett References: <20221025193248.GA21457@srcf.ucam.org> <144cd47e-42dc-2b84-1a90-ea5e080e08a3@redhat.com> <20221025204043.GA23306@srcf.ucam.org> <20221025234040.GA27673@srcf.ucam.org> <20221026204920.GA15326@srcf.ucam.org> <099dee98-8aeb-af36-828c-110f5ac6e9a3@redhat.com> <20221027091123.GA28089@srcf.ucam.org> <933be908-0bc2-56cc-8d6f-38f2d208ef20@redhat.com> <20221027095249.GA28666@srcf.ucam.org> From: Hans de Goede In-Reply-To: <20221027095249.GA28666@srcf.ucam.org> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US, nl Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Nouveau] [PATCH v5 02/31] drm/i915: Don't register backlight when another backlight should be used (v2) X-BeenThere: nouveau@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Nouveau development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Rafael J . Wysocki" , nouveau@lists.freedesktop.org, Joonas Lahtinen , dri-devel@lists.freedesktop.org, platform-driver-x86@vger.kernel.org, Dmitry Osipenko , amd-gfx@lists.freedesktop.org, linux-acpi@vger.kernel.org, Ben Skeggs , David Airlie , Len Brown , Daniel Dadap , Jani Nikula , intel-gfx , Maarten Lankhorst , Jani Nikula , Mark Gross , Maxime Ripard , Rodrigo Vivi , Mika Westerberg , Andy Shevchenko , Tvrtko Ursulin , Xinhui , Alex Deucher , =?UTF-8?Q?Christian_K=c3=b6nig?= Errors-To: nouveau-bounces@lists.freedesktop.org Sender: "Nouveau" Hi, On 10/27/22 11:52, Matthew Garrett wrote: > On Thu, Oct 27, 2022 at 11:39:38AM +0200, Hans de Goede wrote: > >> The *only* behavior which actually is new in 6.1 is the native GPU >> drivers now doing the equivalent of: >> >> if (acpi_video_get_backlight_type() != acpi_backlight_native) >> return; >> >> In their backlight register paths (i), which is causing the native >> backlight to disappear on your custom laptop setup and on Chromebooks >> (with the Chromebooks case being already solved I hope.). > > It's causing the backlight control to vanish on any machine that isn't > ((acpi_video || vendor interface) || !acpi). Most machines that fall > into that are either weird or Chromebooks or old, but there are machines > that fall into that. I acknowledge that their are machines that fall into this category, but I expect / hope there to be so few of them that we can just DMI quirk our way out if this. I believe the old group to be small because: 1. Generally speaking the "native" control method is usually not present on the really old (pre ACPI video spec) mobile GPUs. 2. On most old laptops I would still expect there to be a vendor interface too, and if both get registered standard desktop environments will prefer the vendor one, so then we need a native DMI quirk to disable the vendor interface anyways and we already have a bunch of those, so some laptops in this group are already covered by DMI quirks. And a fix for the Chromebook case is already in Linus' tree, which just leaves the weird case, of which there will hopefully be only a few. I do share your worry that this might break some machines, but the only way to really find out is to get this code out there I'm afraid. I have just written a blog post asking for people to check if their laptop might be affected; and to report various details to me of their laptop is affected: https://hansdegoede.dreamwidth.org/26548.html Lets wait and see how this goes. If I get (too) many reports then I will send a revert of the addition of the: if (acpi_video_get_backlight_type() != acpi_backlight_native) return; check to the i915 / radeon / amd / nouveau drivers. (And if I only get a couple of reports I will probably just submit DMI quirks for the affected models). Regards, Hans