From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [patch] kconfig: unify GENERIC_ISA_DMA and ISA_DMA_API Date: Wed, 26 Jan 2011 11:29:08 +0000 Message-ID: <20110126112908.GD2562@n2100.arm.linux.org.uk> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , Ralf Baechle , Kyle McMartin , James Bottomley , Benjamin Herrenschmidt , Thomas Gleixner , "H. Peter Anvin" , Ingo Molnar , "David S. Miller" , Greg Kroah-Hartman , Randy Dunlap , x86@kernel.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org To: David Rientjes Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, Jan 25, 2011 at 05:06:28PM -0800, David Rientjes wrote: > CONFIG_GENERIC_ISA_DMA and CONFIG_ISA_DMA_API usually have dependencies > on one another depending on the architecture and generic kernel code uses > either to determine whether an ISA-style DMA API is configured. Wrong. GENERIC_ISA_DMA enables support for the standard ISA DMA allocator found in kernel/dma.c ISA_DMA_API says that a platform supports the ISA DMA interfaces. An architecture can provide the ISA DMA interfaces, but not use the standard ISA DMA allocator found in kernel/dma.c. Such as the one in arch/arm/kernel/dma.c. So on ARM, we have platforms where ISA_DMA_API=y but GENERIC_ISA_DMA=n. > This patch unifies both options and consolidates them into a single > option: CONFIG_GENERIC_ISA_DMA. It is also a prerequisite for a 1% text > savings for a future x86 patch that allows these options to be disabled > on that architecture when CONFIG_ZONE_DMA also becomes configurable. NAK. This is wrong.