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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85F5DC433F5 for ; Mon, 1 Nov 2021 19:36:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E91760187 for ; Mon, 1 Nov 2021 19:36:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231197AbhKATii (ORCPT ); Mon, 1 Nov 2021 15:38:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:38230 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231186AbhKATib (ORCPT ); Mon, 1 Nov 2021 15:38:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPS id E2F6460187 for ; Mon, 1 Nov 2021 19:35:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1635795356; bh=pGmMH7XDoCPaOLkJdqIqiz33b95UH3OaIJxOXm39sFo=; h=From:To:Subject:Date:In-Reply-To:References:From; b=fpNqy3a63xAPbHFUQOhKoRcdK3wxmGELBJUel54ktyU2uFkvgM/lVZ4nqv/ww/0H8 gd5cKOd1q3JZOgHNMiLjZqZp8fAXMSIKT3fPfYQlkgkqY3tW4dpdP41+xD06nfrITA cyFM9NCqLaeFP+ZzH2E0b9PPVTmHGWZ4vfSH7+B0MjFhtvi8zYVb3JxlhaMv61F3X6 UlAVl+2kFkW9M92G757Qrbu5sWZkCfgeiZKVTXBGVTgXaZFGhhquVtmddgk77+0xdy k3gdfN953nn6WtfX47armhvLk15VRAio5aB6DNE3/JHgR2wVpxJDncyU3ocGnxk93R +WNSxFozoGN8w== From: bugzilla-daemon@bugzilla.kernel.org To: platform-driver-x86@vger.kernel.org Subject: [Bug 214899] ideapad-laptop: platform backlight device not working Date: Mon, 01 Nov 2021 19:35:56 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo drivers_platform_x86@kernel-bugs.osdl.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: Platform_x86 X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: jwrdegoede@fedoraproject.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: drivers_platform_x86@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=3D214899 Hans de Goede (jwrdegoede@fedoraproject.org) changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jwrdegoede@fedoraproject.or | |g --- Comment #2 from Hans de Goede (jwrdegoede@fedoraproject.org) --- What is your kernel commandline? According to your attached dmesg it is em= pty, but that seems unlikely... ? The ideapad-laptop code has this: if (acpi_video_get_backlight_type() =3D=3D acpi_backlight_vendor) { err =3D ideapad_backlight_init(priv); if (err && err !=3D -ENODEV) goto backlight_failed; } And acpi_video_get_backlight_type() is: enum acpi_backlight_type acpi_video_get_backlight_type(void) { ... if (acpi_backlight_cmdline !=3D acpi_backlight_undef) return acpi_backlight_cmdline; if (acpi_backlight_dmi !=3D acpi_backlight_undef) return acpi_backlight_dmi; if (!(video_caps & ACPI_VIDEO_BACKLIGHT)) return acpi_backlight_vendor; if (acpi_osi_is_win8() && backlight_device_get_by_type(BACKLIGHT_RA= W)) return acpi_backlight_native; return acpi_backlight_video; } So the only way that the ideapad backlight can get registered is if: 1. You have acpi_backlight=3Dvendor on your kernel cmdline 2. There is a DMI quirk setting for your model in the kernel which there is not. 3. Your ACPI tables do not implement the ACPI_VIDEO_BACKLIGHT interface, but your dmesg says: [ 2.237329] ACPI: video: Video Device [GFX0] (multi-head: yes rom: no=20 post: no) So this is unlikely, it is still possible though that your DSDT implements = the ACPI video interface but not the backlight part (that would be a first). I cannot tell since the ACPI video interface is not in the DSDT, it is likely defined in one of the SSDT tables. Please attach a full acpidump. Can you try specifying: "acpi_backlight=3Dvideo" on the kernel commandline = and then do: ls /sys/class/backlight And copy and paste the output here. This cmdline option not only helps me d= ebug this, but it should also workaround your backlight issue :) --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=