[PATCH 0/1] iommu/of: Fix request and enable ACS for of_iommu_configure

From: Wang Xingang
Date: Fri May 07 2021 - 08:50:15 EST


From: Xingang Wang <wangxingang5@xxxxxxxxxx>

When request ACS in of_iommu_configure, the pci_acs_init procedure has
already been called. The pci device probe procedure is like the following:
pci_host_common_probe
pci_device_add
pci_acs_init
of_iommu_configure
pci_request_acs

The pci_request_acs() does not work because the pci_acs_init and
pci_enable_acs procedure has already finished, so the ACS is not
enabled as expected. Besides, the ACS is enabled only if IOMMU is
detected and the device is pci.

So this fix 6bf6c24720d33 ("iommu/of: Request ACS from the PCI core
when configuring IOMMU linkage"), add pci_enable_acs() and IOMMU check
to make sure ACS is enabled for the pci_device.

Xingang Wang (1):
iommu/of: Fix request and enable ACS for of_iommu_configure

drivers/iommu/of_iommu.c | 10 +++++++++-
drivers/pci/pci.c | 2 +-
include/linux/pci.h | 1 +
3 files changed, 11 insertions(+), 2 deletions(-)

--
2.19.1