From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752655Ab1IWJGN (ORCPT ); Fri, 23 Sep 2011 05:06:13 -0400 Received: from am1ehsobe005.messaging.microsoft.com ([213.199.154.208]:46279 "EHLO AM1EHSOBE005.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752266Ab1IWJGL (ORCPT ); Fri, 23 Sep 2011 05:06:11 -0400 X-SpamScore: -21 X-BigFish: VPS-21(zz9371K1432N98dKzz1202hzz15d4R8275bhz32i668h839h944h61h) X-Spam-TCS-SCL: 0:0 X-Forefront-Antispam-Report: CIP:163.181.249.109;KIP:(null);UIP:(null);IPVD:NLI;H:ausb3twp02.amd.com;RD:none;EFVD:NLI X-FB-SS: 0, X-WSS-ID: 0LRYX9W-02-2E8-02 X-M-MSG: Date: Fri, 23 Sep 2011 11:05:57 +0200 From: "Roedel, Joerg" To: Felipe Contreras CC: Laurent Pinchart , "linux-omap@vger.kernel.org" , Ohad Ben-Cohen , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] iommu/omap: Fix build error with !IOMMU_SUPPORT Message-ID: <20110923090557.GB16329@amd.com> References: <1316009259-18052-1-git-send-email-joerg.roedel@amd.com> <201109180202.23123.laurent.pinchart@ideasonboard.com> <20110920100146.GA2078@amd.com> <201109201254.39542.laurent.pinchart@ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-OriginatorOrg: amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 22, 2011 at 09:48:27AM -0400, Felipe Contreras wrote: > On Tue, Sep 20, 2011 at 1:54 PM, Laurent Pinchart > wrote: > > On Tuesday 20 September 2011 12:01:46 Roedel, Joerg wrote: > >> On Sat, Sep 17, 2011 at 08:02:22PM -0400, Laurent Pinchart wrote: > >> > On Wednesday 14 September 2011 16:07:39 Joerg Roedel wrote: > >> > > Without this patch it is possible to select the VIDEO_OMAP3 > >> > > driver which then selects OMAP_IOVMM. But the omap iommu > >> > > driver is not compiled without IOMMU_SUPPORT enabled. Fix > >> > > that by forcing OMAP_IOMMU and OMAP_IOVMM are enabled before > >> > > VIDEO_OMAP3 can be selected. > >> > > >> > What about making VIDEO_OMAP3 select IOMMU_SUPPORT instead then ? Your > >> > patch would make the OMAP3 ISP driver disappear from the menu until > >> > IOMMU_SUPPORT gets turned on, which can confuse users. > >> > >> Using 'depends on' rather then 'selects' is common standard in Kconfig. > >> You can't select PCI drivers without selecting PCI first, for example. > > > > You wouldn't expect a PCI driver to work without PCI support. My concern is > > that most OMAP3 ISP users won't know that IOMMU supports is required. Feel > > free to ignore it though :-) > > I agree with Laurent. As a user, why should I care about IOMMU? I just > want this thing. Because enabling IOMMU can have other side-effects on the system and as a user you want to be aware that it is enabled. A user not wanting the iommu driver can just disable it then without the need to de-select all drivers depending on it first. Joerg -- AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632