On Wed, Jun 10, 2020 at 12:18:14PM +0800, Zhangfei Gao wrote: > Some platform devices appear as PCI and have PCI cfg space, > but are actually on the AMBA bus. > They can support PASID via smmu stall feature, but does not > support tlp since they are not real pci devices. > So remove tlp as a PASID dependency. > > Signed-off-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx> > --- > drivers/pci/ats.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c > index 390e92f..8e31278 100644 > --- a/drivers/pci/ats.c > +++ b/drivers/pci/ats.c > @@ -344,9 +344,6 @@ int pci_enable_pasid(struct pci_dev *pdev, int features) > if (WARN_ON(pdev->pasid_enabled)) > return -EBUSY; > > - if (!pdev->eetlp_prefix_path) > - return -EINVAL; > - This check is useful, and follows the PCI specification (4.0r1.0 2.2.10.2 End-End TLP Prefix Processing: "Software should ensure that TLPs containing End-End TLP Prefixes are not sent to components that do not support them.") Why not set the eetlp_prefix_path bit from a PCI quirk? Unlike the stall problem from the other thread, this one looks like a simple design mistake that can be fixed easily in future iterations of the platform: just set the "End-End TLP Prefix Supported" bit in the Device Capability 2 Register of all bridges. Thanks, Jean
