On Wed, Sep 05, 2018 at 11:55:26AM -0500, Bjorn Helgaas wrote:
> On Wed, Sep 05, 2018 at 02:09:54PM +0300, Mika Westerberg wrote:
> > This reverts commit f154a718e6cc0d834f5ac4dc4c3b174e65f3659e.
> >
> > It turns out that errata "PCH PCIe* Controller Root Port (ACSCTLR)
> > Appear As Read Only" has been fixed in 300 series chipsets even if the
> > datasheet [1] claims otherwise. To make ACS working properly on 300
> > series root ports, revert the faulty commit.
>
> So just to confirm, f154a718e6cc ("PCI: Add ACS quirk for Intel 300
> series") was done based on the faulty datasheet, right?
>
> If somebody actually reported a problem with a 300 series chipset, and
> f154a718e6cc resolved it, we wouldn't want to revert it. But I don't see
> anything like that in the f154a718e6cc changelog, so I assume it was just
> based on the faulty datasheet.
Yes, that's correct. I used the information in the datasheet and that
turned out to be wrong.
