diff --git a/arch/arm/mach-omap2/mailbox.c b/arch/arm/mach-omap2/mailbox.c
index 609ea2ded7e388a22ed9c9d59ba888672ebb13ab..a6db1e4f7b6e61032105bb21e2aeb53951f2235f 100644
--- a/arch/arm/mach-omap2/mailbox.c
+++ b/arch/arm/mach-omap2/mailbox.c
@@ -412,7 +412,8 @@ static void __exit omap2_mbox_exit(void)
 	platform_driver_unregister(&omap2_mbox_driver);
 }
 
-module_init(omap2_mbox_init);
+/* must be ready before omap3isp is probed */
+subsys_initcall(omap2_mbox_init);
 module_exit(omap2_mbox_exit);
 
 MODULE_LICENSE("GPL v2");
diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index d8edd979d01b2c3d84ffb49a9d2c3c53829518d9..6899dcd02dfa0e35df014c42651ba4c5b4f6bb67 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -1223,7 +1223,8 @@ static int __init omap_iommu_init(void)
 
 	return platform_driver_register(&omap_iommu_driver);
 }
-module_init(omap_iommu_init);
+/* must be ready before omap3isp is probed */
+subsys_initcall(omap_iommu_init);
 
 static void __exit omap_iommu_exit(void)
 {