From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sun, 30 Jan 2011 17:05:15 +0100 (CET) Received: from localhost.localdomain ([127.0.0.1]:58323 "EHLO duck.linux-mips.net" rhost-flags-OK-OK-OK-FAIL) by eddie.linux-mips.org with ESMTP id S1491142Ab1A3QFL (ORCPT ); Sun, 30 Jan 2011 17:05:11 +0100 Received: from duck.linux-mips.net (duck [127.0.0.1]) by duck.linux-mips.net (8.14.4/8.14.4) with ESMTP id p0UG4kh8031801; Sun, 30 Jan 2011 17:04:46 +0100 Received: (from ralf@localhost) by duck.linux-mips.net (8.14.4/8.14.4/Submit) id p0UG4ikx031799; Sun, 30 Jan 2011 17:04:44 +0100 Date: Sun, 30 Jan 2011 17:04:44 +0100 From: Ralf Baechle To: Takashi Iwai Cc: Andrew Morton , linux-mips@linux-mips.org Subject: Re: mips allmodconfig Message-ID: <20110130160444.GA2876@linux-mips.org> References: <20110125143113.55aea198.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 29114 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Fri, Jan 28, 2011 at 08:34:22AM +0100, Takashi Iwai wrote: > > sound/oss/soundcard.c:69: error: `MAX_DMA_CHANNELS' undeclared here (not in a function) > > sound/oss/soundcard.c:69: error: storage size of `dma_alloc_map' isn't known > > sound/oss/soundcard.c:69: warning: 'dma_alloc_map' defined but not used > > > > In case you happen to be interested in oss drivers ;) > > I took a quick look. The only case where no MAX_DMA_CHANNELS is > defined is only MIPS with CONFIG_GENERIC_ISA_DMA_SUPPORT_BROKEN. > In arch/mips/include/asm/dma.h: > > #ifndef CONFIG_GENERIC_ISA_DMA_SUPPORT_BROKEN > #define MAX_DMA_CHANNELS 8 > #endif > > What is the intention of this ifdef? Uh... It's a while, took a little headscratching until I remembered again and I think the comment of aa414dff4f7bef29457592414551becdca72dd6b is bogus ... CONFIG_GENERIC_ISA_DMA enabled but MAX_DMA_CHANNELS disabled selects a dummy version of the ISA DMA controller API. Some drivers don't have correct dependencies or ifdefs on CONFIG_GENERIC_ISA_DMA or don't have correct fallback strategies in case of CONFIG_GENERIC_ISA_DMA=n. In those cases just leaving MAX_DMA_CHANNELS undefined is useful. This is used on SGI Indigo² systems which have EISA slots but ISA DMA isn't supported yet by Linux. > Takashi (not interested but just bored ;) Very interested boredom ;-) Ralf