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Commit f938aab2 authored by Thierry Reding's avatar Thierry Reding Committed by Joerg Roedel
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iommu/omap: Play nice in multi-platform builds 



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: default avatarNicolas Chauvet <kwizart@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Suman Anna <s-anna@ti.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent a7b67cd5

drivers/iommu/omap-iommu.c

+7 −0
Original line number Diff line number Diff line
@@ -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);