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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 C3BD0C4360F for ; Tue, 2 Apr 2019 12:26:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96AA120882 for ; Tue, 2 Apr 2019 12:26:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730875AbfDBM0e (ORCPT ); Tue, 2 Apr 2019 08:26:34 -0400 Received: from mga17.intel.com ([192.55.52.151]:52519 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730585AbfDBM0d (ORCPT ); Tue, 2 Apr 2019 08:26:33 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Apr 2019 05:26:33 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,300,1549958400"; d="scan'208";a="160630016" Received: from jnikula-mobl3.fi.intel.com (HELO localhost) ([10.237.72.79]) by fmsmga001.fm.intel.com with ESMTP; 02 Apr 2019 05:26:31 -0700 From: Jani Nikula To: Randy Dunlap , Stephen Rothwell , Linux Next Mailing List Cc: intel-gfx , Linux Kernel Mailing List , dri-devel Subject: Re: [Intel-gfx] linux-next: Tree for Mar 29 (i915, no ACPI) In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20190329141831.30fd841f@canb.auug.org.au> Date: Tue, 02 Apr 2019 15:29:09 +0300 Message-ID: <87zhp8zj3e.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 29 Mar 2019, Randy Dunlap wrote: > On 3/28/19 8:18 PM, Stephen Rothwell wrote: >> Hi all, >> >> Changes since 20190328: >> >> The pidfd tree lost its build failures. >> > > on x86_64, when # CONFIG_ACPI is not set/enabled: > > ld: drivers/gpu/drm/i915/intel_panel.o: in function `intel_backlight_device_register': > intel_panel.c:(.text+0x2c49): undefined reference to `backlight_device_register' > ld: drivers/gpu/drm/i915/intel_panel.o: in function `intel_backlight_device_unregister': > intel_panel.c:(.text+0x2d01): undefined reference to `backlight_device_unregister' > > > > Full randconfig file is attached. # CONFIG_ACPI is not set CONFIG_DRM_I915=y CONFIG_BACKLIGHT_CLASS_DEVICE=m drivers/gpu/drm/i915/Kconfig: config DRM_I915 # ... select BACKLIGHT_CLASS_DEVICE if ACPI The above pretty much sums it up. It's been reported before, the earliest I could find was [1]. I've previously suggested patches that would make backlight a dependency instead of selecting it, in line with [2]. However we can't do that in i915 alone without recursive dependencies, and changing all backlight users was met with opposition because "select is convenient". Maybe I'll look at this one of these days, but don't hold your breath. BR, Jani. [1] http://mid.mail-archive.com/CA+r1ZhhmT4DrWtf6MbRQo5EqXwx+LxCqh15Vsu_d9WpftLhnxw@mail.gmail.com [2] Documentation/kbuild/kconfig-language.txt "In general use select only for non-visible symbols (no prompts anywhere) and for symbols with no dependencies." -- Jani Nikula, Intel Open Source Graphics Center