Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during of_xlate().

Fixes: 46d1fb072e76 ("iommu/dart: Add DART iommu driver")
Cc: stable@vger.kernel.org	# 5.15
Cc: Sven Peter <sven@kernel.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/iommu/apple-dart.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index 95a4e62b8f63..9804022c7f59 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -802,6 +802,8 @@ static int apple_dart_of_xlate(struct device *dev,
 	struct apple_dart *cfg_dart;
 	int i, sid;
 
+	put_device(&iommu_pdev->dev);
+
 	if (args->args_count != 1)
 		return -EINVAL;
 	sid = args->args[0];
-- 
2.49.1