acpi_dev_hid_uid_match expects a null pointer for UID if it doesn't exist. The acpihid_map_entry contains a char buffer for holding the UID. If no UID was provided in the IVRS table, this buffer will be zeroed. If we pass in a null string, acpi_dev_hid_uid_match will return false because it will try and match an empty string to the ACPI UID of the device.
Fixes: ae5e6c6439c3 ("iommu/amd: Switch to use acpi_dev_hid_uid_match()") Signed-off-by: Raul E Rangel <rran...@chromium.org> --- drivers/iommu/amd_iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 20cce366e951..06f603366cb1 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -125,7 +125,8 @@ static inline int get_acpihid_device_id(struct device *dev, return -ENODEV; list_for_each_entry(p, &acpihid_map, list) { - if (acpi_dev_hid_uid_match(adev, p->hid, p->uid)) { + if (acpi_dev_hid_uid_match(adev, p->hid, + p->uid[0] ? p->uid : NULL)) { if (entry) *entry = p; return p->devid; -- 2.26.2.645.ge9eca65c58-goog _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu