On Mon, Jan 06, 2025 at 12:34:00PM -0800, Tushar Dave wrote: > On 1/2/25 10:40, Jason Gunthorpe wrote: > > On Fri, Dec 13, 2024 at 12:29:42PM -0800, Tushar Dave wrote: > > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > > index dc663c0ca670..fc1c37910d1c 100644 > > > --- a/Documentation/admin-guide/kernel-parameters.txt > > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > > @@ -4654,11 +4654,10 @@ > > > Format: > > > <ACS flags>@<pci_dev>[; ...] > > > Specify one or more PCI devices (in the format > > > - specified above) optionally prepended with flags > > > - and separated by semicolons. The respective > > > - capabilities will be enabled, disabled or > > > - unchanged based on what is specified in > > > - flags. > > > + specified above) prepended with flags and separated > > > + by semicolons. The respective capabilities will be > > > + enabled, disabled or unchanged based on what is > > > + specified in flags. > > > ACS Flags is defined as follows: > > > bit-0 : ACS Source Validation > > > @@ -4673,7 +4672,7 @@ > > > '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 > > > > Is this an unrelated change? The format of the command line shouldn't > > be changed to fix the described bug, why is the documentation changed? > > The documentation as it is (i.e. without my patch), is not correct. > > IOW, config_acs parameter does require flags and it is not optional. Without > flags it results into "ACS Flags missing". Therefore I remove word > "optionally" from the documentation text. > > Secondly, the syntax in the example 'pci=config_acs=10x' is incorrect. The > correct syntax should be 'pci=config_acs=10x@pci:0:0' that 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. I'd suggest a separate patch to fix the documentation so we don't try to relate the doc changes with the code changes.
