From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH 2/5] iommu/omap: Permanently keep iommu_dev pointer in arch_data Date: Fri, 7 Apr 2017 16:35:20 +0200 Message-ID: <20170407143520.GB7266@8bytes.org> References: <1490962248-12602-1-git-send-email-joro@8bytes.org> <1490962248-12602-3-git-send-email-joro@8bytes.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Suman Anna Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Joerg Roedel , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: iommu@lists.linux-foundation.org Hi Suman, On Mon, Apr 03, 2017 at 03:35:46PM -0500, Suman Anna wrote: > > + iommu = platform_get_drvdata(pdev); > > + if (!iommu) { > > + of_node_put(np); > > + return -EINVAL; > > + } > > This change is causing the issues. OMAP IOMMU driver is not probed yet, > but this gets called during the driver's init function in > bus_set_iommu() and bus's iommu_ops gets set to NULL. The add_device > today is used to add the linking to an IOMMU device (currently name > primarily to support the legacy non-DT mode which is no longer an issue, > but a dev pointer can be used instead here, and the real enabling is > done during the domain's attach_dev callback. Yeah, okay. Solving this problem requires more sophisticated handling in the iommu core code, which is not implemented yet. I drop this patch for now and do the device-linking and group-handling in attach_dev. This makes iommu-groups on omap useless for now, but it is a start. Joerg