From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754243Ab2KWRtY (ORCPT ); Fri, 23 Nov 2012 12:49:24 -0500 Received: from cpsmtpb-ews02.kpnxchange.com ([213.75.39.5]:62873 "EHLO cpsmtpb-ews02.kpnxchange.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752460Ab2KWRtX (ORCPT ); Fri, 23 Nov 2012 12:49:23 -0500 Message-ID: <1353692960.1420.26.camel@x61.thuisdomein> Subject: Re: nouveau driver fails to build From: Paul Bolle To: Helmut Jarausch Cc: linux-kernel@vger.kernel.org, Michal Marek , linux-kbuild@vger.kernel.org Date: Fri, 23 Nov 2012 18:49:20 +0100 In-Reply-To: <1353690805.30841.0@numa-i> References: <1353681769.29421.0@numa-i> <1353684679.1420.7.camel@x61.thuisdomein> <1353690805.30841.0@numa-i> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4 (3.4.4-2.fc17) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 23 Nov 2012 17:49:20.0736 (UTC) FILETIME=[DDD71E00:01CDC9A2] X-RcptDomain: vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-11-23 at 18:13 +0100, Helmut Jarausch wrote: > On 11/23/2012 04:31:19 PM, Paul Bolle wrote: > > On Fri, 2012-11-23 at 15:42 +0100, Helmut Jarausch wrote: > > > with 3.7_rc6 and > > > > > > CONFIG_ACPI_VIDEO=m > > > CONFIG_DRM=y > > > CONFIG_DRM_KMS_HELPER=y > > > CONFIG_DRM_TTM=y > > > CONFIG_DRM_NOUVEAU=y > > > CONFIG_NOUVEAU_DEBUG=5 > > > CONFIG_NOUVEAU_DEBUG_DEFAULT=3 > > > CONFIG_DRM_NOUVEAU_BACKLIGHT=y > > > > > > with/ without > > > CONFIG_DRM_LOAD_EDID_FIRMWARE=y > > > > > > > > > The kernel fails to build with > > > drivers/built-in.o: In function `nouveau_acpi_edid': > > > (.text+0x12bf21): undefined reference to `acpi_video_get_edid' > > > > > > > > > What am I missing? > > > > I'd guess it should build (at least without this error) with > > CONFIG_ACPI_VIDEO=y. Is that correct? > > Yes, but this is very unnatural. > > To get CONFIG_ACPI_VIDEO=y I need to have VIDEO_OUTPUT_CONTROL=y > for which I have to select the Intel GMA500 Stub Driver although I don't > have such a device and therefore don't need that driver. > Furthermore, I had to chase through quite some flags to find this. > > If it's not a bug, it's surprising, at least. 0) It puzzles me too. 1) The problem is in Nouveau's Kconfig: config DRM_NOUVEAU tristate "Nouveau (nVidia) cards" [...] select ACPI_VIDEO if ACPI && X86 && BACKLIGHT_CLASS_DEVICE && VIDEO_OUTPUT_CONTROL && INPUT [...] and its Makefile: # other random bits [...] nouveau-$(CONFIG_ACPI) += nouveau_acpi.o [...] obj-$(CONFIG_DRM_NOUVEAU)+= nouveau.o 2) Now, with DRM_NOUVEAU=y and ACPI_VIDEO=m nouveau_acpi.o will be made builtin (which fails with the error Helmut ran into). The puzzling part is that ACPI_VIDEO will only be selected (ie, made into a 'y') if all dependencies of that select statement are 'y' too. (Note that these dependencies are identical to the dependencies of ACPI_VIDEO's config entry. That can be no coincidence.) 3) But I would expect ACPI_VIDEO to be selected if the dependencies of that select statement are either 'y' or 'm'. And then Helmut's .config should trigger some warning about selecting a symbol with unmet dependencies, or whatever, shouldn't it? (Because some of ACPI_VIDEO's dependencies are still 'm'.) 4) I'm CC-ing the Kconfig people to tell us whether the current behavior is as designed or a bug. If it's not a bug the DRM_NOUVEAU config entry might need to be changed. Paul Bolle