The documentation used to say: > For example, > pci=config_acs=10x > would configure all devices that support ACS to enable P2P Request > Redirect, disable Translation Blocking, and leave Source Validation > unchanged from whatever power-up or firmware set it to. However, a flag specification always needs to be suffixed with "@" and a PCI device string, which is missing in this example. It needs to be suffixed with "@pci:0:0" to configure all devices that support ACS in particular. Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx> --- Documentation/admin-guide/kernel-parameters.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index ee2984e46c06..5611903c27a9 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4604,7 +4604,7 @@ '1' – force enabled 'x' – unchanged For example, - pci=config_acs=10x + pci=config_acs=10x@pci:0:0 would configure all devices that support ACS to enable P2P Request Redirect, disable Translation Blocking, and leave Source --- base-commit: 46a0057a5853cbdb58211c19e89ba7777dc6fd50 change-id: 20240911-acs-3043a2737cc9 Best regards, -- Akihiko Odaki <akihiko.odaki@xxxxxxxxxx>