From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH] ata: libata depends on HAS_DMA Date: Fri, 15 May 2009 13:16:30 +0200 Message-ID: <200905151316.31521.arnd@arndb.de> References: <20090513043409.GA13577@cynthia.pants.nu> <20090514091928R.fujita.tomonori@lab.ntt.co.jp> <4A0CFE1F.5080409@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4A0CFE1F.5080409@gmail.com> Content-Disposition: inline Sender: linux-m68k-owner@vger.kernel.org To: Tejun Heo Cc: FUJITA Tomonori , hancockrwd@gmail.com, alan@lxorguk.ukuu.org.uk, flar@allandria.com, schmitz@biophys.uni-duesseldorf.de, linux-kernel@vger.kernel.org, jgarzik@pobox.com, linux-ide@vger.kernel.org, takata@linux-m32r.org, geert@linux-m68k.org, linux-m68k@vger.kernel.org, ysato@users.sourceforge.jp List-Id: linux-ide@vger.kernel.org On Friday 15 May 2009, Tejun Heo wrote: > FUJITA Tomonori wrote: > > Can libata call dma_supported() per device to decide DMA or PIO mod= e? > > Then, we can solve this problem by add dummy DMA API (just calls BU= G) > > on such architectures, without Kconfig magic or adding ifdef (like = the > > old ide stack does), I think. That would be the !CONFIG_PCI half of the old include/asm-generic/dma-mapping.h file that you just removed, right? In general, I'd prefer keeping the asm-generic/dma-mapping-broken.h implementation that gives us a compile-time error, but maybe there is an even better option based on the mn10300 implementation which basically pretends everything works with just page_to_phys() mappings. > Sure it can. =A0Which specific drivers are we talking about? The main problem is libata-core.c, which references DMA mapping API calls that are only implemented on architectures setting CONFIG_HAS_DMA. Arnd <>< -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754276AbZEOLST (ORCPT ); Fri, 15 May 2009 07:18:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752592AbZEOLR7 (ORCPT ); Fri, 15 May 2009 07:17:59 -0400 Received: from moutng.kundenserver.de ([212.227.126.188]:51762 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751956AbZEOLR6 convert rfc822-to-8bit (ORCPT ); Fri, 15 May 2009 07:17:58 -0400 From: Arnd Bergmann To: Tejun Heo Subject: Re: [PATCH] ata: libata depends on HAS_DMA Date: Fri, 15 May 2009 13:16:30 +0200 User-Agent: KMail/1.9.9 Cc: FUJITA Tomonori , hancockrwd@gmail.com, alan@lxorguk.ukuu.org.uk, flar@allandria.com, schmitz@biophys.uni-duesseldorf.de, linux-kernel@vger.kernel.org, jgarzik@pobox.com, linux-ide@vger.kernel.org, takata@linux-m32r.org, geert@linux-m68k.org, linux-m68k@vger.kernel.org, ysato@users.sourceforge.jp References: <20090513043409.GA13577@cynthia.pants.nu> <20090514091928R.fujita.tomonori@lab.ntt.co.jp> <4A0CFE1F.5080409@gmail.com> In-Reply-To: <4A0CFE1F.5080409@gmail.com> X-Face: I@=L^?./?$U,EK.)V[4*>`zSqm0>65YtkOe>TFD'!aw?7OVv#~5xd\s,[~w]-J!)|%=]>=?utf-8?q?+=0A=09=7EohchhkRGW=3F=7C6=5FqTmkd=5Ft=3FLZC=23Q-=60=2E=60Y=2Ea=5E?= =?utf-8?q?3zb?=) =?utf-8?q?+U-JVN=5DWT=25cw=23=5BYo0=267C=26bL12wWGlZi=0A=09=7EJ=3B=5Cwg?= =?utf-8?q?=3B3zRnz?=,J"CT_)=\H'1/{?SR7GDu?WIopm.HaBG=QYj"NZD_[zrM\Gip^U MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200905151316.31521.arnd@arndb.de> X-Provags-ID: V01U2FsdGVkX193nZ5mTixXcBwTaX5pgSTA0ziV1N549JvUnel A24eTawpnSdRUZo6M8nbmPNYl4QR6qtOjk5iyJtDL3dq0lolMV 1zH3EM9HFzwfUMVc7ijyg== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 15 May 2009, Tejun Heo wrote: > FUJITA Tomonori wrote: > > Can libata call dma_supported() per device to decide DMA or PIO mode? > > Then, we can solve this problem by add dummy DMA API (just calls BUG) > > on such architectures, without Kconfig magic or adding ifdef (like the > > old ide stack does), I think. That would be the !CONFIG_PCI half of the old include/asm-generic/dma-mapping.h file that you just removed, right? In general, I'd prefer keeping the asm-generic/dma-mapping-broken.h implementation that gives us a compile-time error, but maybe there is an even better option based on the mn10300 implementation which basically pretends everything works with just page_to_phys() mappings. > Sure it can.  Which specific drivers are we talking about? The main problem is libata-core.c, which references DMA mapping API calls that are only implemented on architectures setting CONFIG_HAS_DMA. Arnd <><