From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH v2 2/4] iommu/omap: Play nice in multi-platform builds Date: Mon, 09 Feb 2015 11:31:13 +0200 Message-ID: <4074084.ChUOO287C1@avalon> References: <1423219448-22683-1-git-send-email-thierry.reding@gmail.com> <1423219448-22683-3-git-send-email-thierry.reding@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1423219448-22683-3-git-send-email-thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@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: Thierry Reding Cc: Nicolas Chauvet , Tony Lindgren , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: iommu@lists.linux-foundation.org Hi Thierry, Thank you for the patch. On Friday 06 February 2015 11:44:06 Thierry Reding wrote: > From: Thierry Reding > > The OMAP IOMMU driver unconditionally executes code and registers a > struct iommu_ops with the platform bus irrespective of whether it runs > on an OMAP SoC or not. This causes problems in multi-platform kernels > where drivers for other SoCs will no longer be able to register their > own struct iommu_ops or even try to use a struct iommu_ops for an IOMMU > that obviously isn't there. > > The smallest fix I could think of is to check for the existence of any > OMAP IOMMU devices in the device tree and skip initialization otherwise. > > This fixes a problem on Tegra20 where the DRM driver will try to use the > obviously non-existent OMAP IOMMU. > > Reported-by: Nicolas Chauvet > Cc: Tony Lindgren > Cc: Suman Anna > Cc: Laurent Pinchart > Signed-off-by: Thierry Reding Acked-by: Laurent Pinchart > --- > Changes in v2: > - do not fix up module exit function since it's dead code > - drop reference to struct device_node > > drivers/iommu/omap-iommu.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c > index f59f857b702e..a4ba851825c2 100644 > --- a/drivers/iommu/omap-iommu.c > +++ b/drivers/iommu/omap-iommu.c > @@ -1376,6 +1376,13 @@ static int __init omap_iommu_init(void) > struct kmem_cache *p; > const unsigned long flags = SLAB_HWCACHE_ALIGN; > size_t align = 1 << 10; /* L2 pagetable alignement */ > + struct device_node *np; > + > + np = of_find_matching_node(NULL, omap_iommu_of_match); > + if (!np) > + return 0; > + > + of_node_put(np); > > p = kmem_cache_create("iopte_cache", IOPTE_TABLE_SIZE, align, flags, > iopte_cachep_ctor); -- Regards, Laurent Pinchart