iommu: Check for iommu_ops == NULL in iommu_probe_device()

This check needs to be there and got lost at some point
during development. Add it again.

Fixes: 641fb0efbff0 ('iommu/of: Don't call iommu_ops->add_device directly')
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: kernelci.org bot <bot@kernelci.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index a2131751dcff..3ed4db334341 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -114,10 +114,14 @@ void iommu_device_unregister(struct iommu_device *iommu)
 int iommu_probe_device(struct device *dev)
 {
         const struct iommu_ops *ops = dev->bus->iommu_ops;
+        int ret = -EINVAL;
 
         WARN_ON(dev->iommu_group);
 
-        return ops->add_device(dev);
+        if (ops)
+                ret = ops->add_device(dev);
+
+        return ret;
 }
 
 void iommu_release_device(struct device *dev)