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-rw-r--r--drivers/iommu/amd_iommu.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 6b0760dafb3e..b319e51c379b 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -140,10 +140,14 @@ static struct lock_class_key reserved_rbtree_key;
static inline int match_hid_uid(struct device *dev,
struct acpihid_map_entry *entry)
{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
const char *hid, *uid;
- hid = acpi_device_hid(ACPI_COMPANION(dev));
- uid = acpi_device_uid(ACPI_COMPANION(dev));
+ if (!adev)
+ return -ENODEV;
+
+ hid = acpi_device_hid(adev);
+ uid = acpi_device_uid(adev);
if (!hid || !(*hid))
return -ENODEV;