[PATCH 2/2] iommu: add warning when sharing groups
Sinan Kaya
okaya at codeaurora.org
Tue Feb 14 13:25:22 PST 2017
The ACS requirement has been obscured in the current code and is only
known by certain individuals who happen to read the code. Print out a
warning with ACS path failure when ACS requirement is not met.
Signed-off-by: Sinan Kaya <okaya at codeaurora.org>
---
drivers/iommu/iommu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index dbe7f65..049ee0a 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -811,6 +811,9 @@ struct iommu_group *pci_device_group(struct device *dev)
if (IS_ERR(group))
return NULL;
+ if (pci_is_root_bus(bus))
+ dev_warn_once(&pdev->dev, "using shared group due to ACS path failure\n");
+
return group;
}
--
1.9.1
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