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 E0C9CC38A2D for ; Mon, 24 Oct 2022 20:41:14 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F030F10E28E; Mon, 24 Oct 2022 20:40:59 +0000 (UTC) X-Greylist: delayed 595 seconds by postgrey-1.36 at gabe; Mon, 24 Oct 2022 20:40:55 UTC Received: from cavan.codon.org.uk (irc.codon.org.uk [IPv6:2a00:1098:84:22e::2]) by gabe.freedesktop.org (Postfix) with ESMTPS id 794B910E09F; Mon, 24 Oct 2022 20:40:55 +0000 (UTC) Received: by cavan.codon.org.uk (Postfix, from userid 1000) id 9492F40A6A; Mon, 24 Oct 2022 21:30:57 +0100 (BST) Date: Mon, 24 Oct 2022 21:30:57 +0100 From: Matthew Garrett To: Hans de Goede Message-ID: <20221024203057.GA28675@srcf.ucam.org> References: <20220825143726.269890-1-hdegoede@redhat.com> <20220825143726.269890-3-hdegoede@redhat.com> <42a5f2c9-a1dc-8fc0-7334-fe6c390ecfbb@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <42a5f2c9-a1dc-8fc0-7334-fe6c390ecfbb@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) 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: Pan@freedesktop.org, "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 , Christian =?iso-8859-1?Q?K=F6nig?= Errors-To: nouveau-bounces@lists.freedesktop.org Sender: "Nouveau" On Tue, Sep 27, 2022 at 01:04:52PM +0200, Hans de Goede wrote: > So to fix this we need to make acpi_video_get_backlight_type() > return native on the Acer Chromebook Spin 713. Isn't the issue broader than that? Unless the platform is Windows 8 or later, we'll *always* (outside of some corner cases) return acpi_backlight_vendor if there's no ACPI video interface. This is broken for any platform that implements ACPI but relies on native video control, which is going to include a range of Coreboot platforms, not just Chromebooks. I think for this to work correctly you need to have the infrastructure be aware of whether or not a vendor interface exists, which means having to handle cleanup if a vendor-specific module gets loaded later.