From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCHv7 05/12] iommu/core: add ops->{bound,unbind}_driver() Date: Mon, 30 Dec 2013 14:45:23 +0100 Message-ID: <20131230134522.GB2799@8bytes.org> References: <1386835033-4701-1-git-send-email-hdoyu@nvidia.com> <1386835033-4701-6-git-send-email-hdoyu@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1386835033-4701-6-git-send-email-hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> 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: Hiroshi Doyu Cc: mark.rutland-5wv7dgnIgG8@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org, swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, Stephen Warren , will.deacon-5wv7dgnIgG8@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Thu, Dec 12, 2013 at 09:57:06AM +0200, Hiroshi Doyu wrote: > ops->{bound,unbind}_driver() functions are called at > BUS_NOTIFY_{BOUND,UNBIND}_DRIVER respectively. > > This is necessary to control the device population order. IOMMU master > devices depend on an IOMMU device instanciation. IOMMU master devices > can be registered to an IOMMU only after it's successfully > populated. This IOMMU registration is done via > ops->bound_driver(). Currently this population can be deferred if > depending IOMMU device hasn't yet been populated in driver core. This > cannot be done via ops->add_device() since after add_device() device's > population/instanciation can be still deferred via probe(). How about doing dependency checking in the add/remove_device callbacks instead? When a device is about to be initialized where the IOMMU is not set up yet, just setup the IOMMU first before initializing the device? Joerg