From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757624Ab0EAWpS (ORCPT ); Sat, 1 May 2010 18:45:18 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:50752 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757134Ab0EAWpN (ORCPT ); Sat, 1 May 2010 18:45:13 -0400 Date: Sat, 1 May 2010 23:44:29 +0100 From: Russell King - ARM Linux To: Dan Williams Cc: Linus Walleij , Linus WALLEIJ , "akpm@linux-foundation.org" , Grant Likely , "linux-arm-kernel@lists.infradead.org" , "linux-mmc@vger.kernel.org" , STEricsson_nomadik_linux , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 00/11] ARM: PrimeCell DMA Interface v5 Message-ID: <20100501224429.GA17693@n2100.arm.linux.org.uk> References: <1270681920-4461-1-git-send-email-linus.walleij@stericsson.com> <20100422110025.GC20008@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 01, 2010 at 03:00:09PM -0700, Dan Williams wrote: > Just to clarify are you nak'ing these patches for upstream inclusion > until this testing occurs? Or do we just need a !ARCH_VERSATILE > somewhere to allow any incompatibilities to be worked out later > in-tree? What I don't want to do is to get into the situation where we throw this patchset into the kernel and then find that we have to invent a whole new implementation in the various primecell drivers to support the Versatile hardware. Versatile has some MUXing on three of the DMA signals, so (eg) we really don't want UARTs claiming DMAs just because they're in existence and not in use - that would prevent DMAs from being used for (eg) AACI or MMC. The alternative is that we could just take the attitude that Versatile/ Realview will never have DMA support implemented, but that seems rather silly, as they've tended to be the first platforms I get new CPU architectures for. (This is why DMA coherency stuff on new architectures tends to be left for others to do...)