From: Thierry Reding <[email protected]> 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 <[email protected]> Cc: Tony Lindgren <[email protected]> Cc: Suman Anna <[email protected]> Cc: Laurent Pinchart <[email protected]> Signed-off-by: Thierry Reding <[email protected]> --- drivers/iommu/omap-iommu.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c index bbb7dcef02d3..e4d4f133a3b3 100644 --- a/drivers/iommu/omap-iommu.c +++ b/drivers/iommu/omap-iommu.c @@ -1377,6 +1377,9 @@ static int __init omap_iommu_init(void) const unsigned long flags = SLAB_HWCACHE_ALIGN; size_t align = 1 << 10; /* L2 pagetable alignement */ + if (!of_find_matching_node(NULL, omap_iommu_of_match)) + return 0; + p = kmem_cache_create("iopte_cache", IOPTE_TABLE_SIZE, align, flags, iopte_cachep_ctor); if (!p) @@ -1394,6 +1397,9 @@ subsys_initcall(omap_iommu_init); static void __exit omap_iommu_exit(void) { + if (!of_find_matching_node(NULL, omap_iommu_of_match)) + return; + kmem_cache_destroy(iopte_cachep); platform_driver_unregister(&omap_iommu_driver); -- 2.1.3 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
