From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757819Ab0EAXZz (ORCPT ); Sat, 1 May 2010 19:25:55 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:33842 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755339Ab0EAXZx convert rfc822-to-8bit (ORCPT ); Sat, 1 May 2010 19:25:53 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=kUMJ4BmtkXpHGI7haQD2UP80+2JH7oZh8HN0ZQKAtvgTL219T4TtpuLu79o1XLOhr1 q5/179Qu73OJTpUlh/HsgLb3E/Vg2wfEAu7TfpMjZ831rcD8C9orpBfn+QQXqG8hsh6C zSZOPb1fhdrDv9P/Hoo7r1NhoeMn0fY0B3QQA= MIME-Version: 1.0 In-Reply-To: <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> <20100501224429.GA17693@n2100.arm.linux.org.uk> Date: Sat, 1 May 2010 16:25:52 -0700 X-Google-Sender-Auth: 71da49ad79b97688 Message-ID: Subject: Re: [PATCH 00/11] ARM: PrimeCell DMA Interface v5 From: Dan Williams To: Russell King - ARM Linux 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" Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 1, 2010 at 3:44 PM, Russell King - ARM Linux wrote: > 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...) Ok, it will be good to have this approach vetted on a challenging arch. We'll see where things stand when the merge window opens. -- Dan