[+cc ARM, IOMMU folks; I don't know the answer, but maybe they do] On Fri, Jul 19, 2024 at 11:01:11PM +0800, steven wrote: > Hello, > > I am a new person in PCI, I am trying to do something for iommu > group on arm64 platform, I found if I boot the linux (5.10 kernel) > kernel using UEFI + ACPI, it will work correctly. But if I boot it > using UEFI + DTB, the iommu group not work, only one group present. > > I read the code, found that pci_acs_enable is set to 1 during > acpi_init, but I can not find any code for dtb booting, so it will > return "disable_acs_redir " during call pci_enable_acs. > > static void pci_enable_acs(struct pci_dev *dev) > { > if (!pci_acs_enable) > goto disable_acs_redir; > > if (!pci_dev_specific_enable_acs(dev)) > goto disable_acs_redir; > > pci_std_enable_acs(dev); > > > > > SO, is it not support in dtb? >