Re: [PATCH 09/13] PCI/P2PDMA: Document ACS egress control handling

[Leon Romanovsky]

On Tue, Aug 04, 2026 at 04:01:41PM -0600, Logan Gunthorpe wrote:
> 
> 
> On 2026-08-02 09:09, Leon Romanovsky wrote:
> > +ACS P2P Egress Control does not by itself force a transaction upstream. A
> > +clear Egress Control Vector bit for the peer port permits direct routing; a
> > +set bit redirects the request upstream when P2P Request Redirect is enabled.
> > +When Request Redirect is disabled, a set vector bit causes an ACS Violation
> > +instead. The kernel evaluates these controls together and routes P2P DMA
> > +through the host bridge when the direct path is blocked or cannot be
> > +determined.
> 
> One small nit here: I'd put commas around "by itself" to make it read a
> little easier:
> 
> "ACS P2P Egress Control does not, by itself, force a transaction..."
> 
> Other than that:
> 
> Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>

Thanks for the review. I understand the effort involved and truly
appreciate it.