[PATCH v4 02/16] iommu/amd: Handle race between registration and device probe

Robin Murphy robin.murphy at arm.com
Mon Aug 15 09:20:03 PDT 2022


As for the Intel driver, make sure the AMD driver can cope with seeing
.probe_device calls without having to wait for all known instances to
register first.

Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---

v4: No change

 drivers/iommu/amd/iommu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 65b8e4fd8217..5ed9fd40d2a7 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1851,6 +1851,10 @@ static struct iommu_device *amd_iommu_probe_device(struct device *dev)
 	if (!iommu)
 		return ERR_PTR(-ENODEV);
 
+	/* Not registered yet? */
+	if (!iommu->iommu.ops)
+		return ERR_PTR(-ENODEV);
+
 	if (dev_iommu_priv_get(dev))
 		return &iommu->iommu;
 
-- 
2.36.1.dirty




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