From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Cohen Subject: Re: [PATCH 0/4] iommu: Prevent oops in iommu_get() and while arch_iommu is in use Date: Fri, 25 Mar 2011 17:44:38 +0200 Message-ID: References: <4D8CB217.1050909@maxwell.research.nokia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-iw0-f174.google.com ([209.85.214.174]:58654 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753713Ab1CYPok convert rfc822-to-8bit (ORCPT ); Fri, 25 Mar 2011 11:44:40 -0400 Received: by iwn34 with SMTP id 34so1180981iwn.19 for ; Fri, 25 Mar 2011 08:44:39 -0700 (PDT) In-Reply-To: <4D8CB217.1050909@maxwell.research.nokia.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Sakari Ailus Cc: "linux-omap@vger.kernel.org" , "Doyu Hiroshi (Nokia-D/Helsinki)" , Laurent Pinchart , Cohen David Abraham On Fri, Mar 25, 2011 at 5:17 PM, Sakari Ailus wrote: > Hi, Hi Sakari, > > [Resend: the patches were accidentally sent to linux-media instead. > Apologies.] > > This patchset is aimed to fix a problem in arch_iommu implementation > references. When an actual arch_iommu implementation is not loaded wh= ile > iommu_get() is being called results to a kernel oops, as well as > removing an arch_iommu implementation which is in use. > > This patchset fixes both issues. Sounds nice. > > The patchset assumes the arch_iommu is uninstalled at module unload > time. Is this an acceptable requirement? I can't see a reason why this assumption could be wrong. In my point of view it's acceptable. Let's see Hiroshi's. Regards, David Cohen > > Serialisation of the access to arch_iommu is done using mutex called > arch_iommu_mutex. > > module_put() doesn't need to have the arch_iommu_mutex since when thi= s > gets called there won't be any users on the arch_iommu anyway. > > Comments are welcome. :-) > > Cheers, > > -- > Sakari Ailus > sakari.ailus@maxwell.research.nokia.com > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap"= in > the body of a message to majordomo@vger.kernel.org > More majordomo info at =C2=A0http://vger.kernel.org/majordomo-info.ht= ml > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html