Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751924AbaJ0LCT (ORCPT ); Mon, 27 Oct 2014 07:02:19 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:30813 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750967AbaJ0LCS (ORCPT ); Mon, 27 Oct 2014 07:02:18 -0400 X-IronPort-AV: E=Sophos;i="5.04,795,1406592000"; d="scan'208";a="186427766" Message-ID: <544E2637.8000902@citrix.com> Date: Mon, 27 Oct 2014 11:02:15 +0000 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Icedove/24.5.0 MIME-Version: 1.0 To: Stefano Stabellini , Ian Campbell CC: "xen-devel@lists.xensource.com" , "linux@arm.linux.org.uk" , Catalin Marinas , Will Deacon , "linux-kernel@vger.kernel.org" , "david.vrabel@citrix.com" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [Xen-devel] [PATCH v4 3/7] [RFC] arm/arm64: introduce is_dma_coherent References: <1412941908-5850-3-git-send-email-stefano.stabellini@eu.citrix.com> <20141010120702.GI7755@arm.com> <20141013125725.GA19156@arm.com> <20141024104746.GC1955@localhost> <20141024154353.GE20534@e104818-lin.cambridge.arm.com> <1414251629.3584.20.camel@citrix.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25/10/14 17:15, Stefano Stabellini wrote: > On Sat, 25 Oct 2014, Ian Campbell wrote: >> On Sat, 2014-10-25 at 14:29 +0100, Stefano Stabellini wrote: >>> >>> Your suggestions and looking more at the code gave me another idea, that >>> I think is clean and at the same time suitable for 3.18. >>> What do you think of the following? It is simple, self-contained and >>> doesn't need a new flag in struct device. >> >> of_dma_is_coherent looks to be quite expensive though (walks up the >> Device Tree doing strcmps on each property of each node until it finds >> the one it is looking for. > > It takes spin_locks too! > Too bad, I think I'll have to ditch it. In that case I'l try the new > flag in struct device approach. If you're having to make changes to struct device, this is looking like a series for 3.19 (not 3.18). David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/