On Wed, 18 Sep 2019 13:09:18 +0100 Andrew Murray <andrew.murray@xxxxxxx> wrote: > On Wed, Sep 18, 2019 at 02:02:59PM +0200, Steffen Liebergeld wrote: > > On 18/09/2019 12:42, Andrew Murray wrote: > > > On Tue, Sep 17, 2019 at 08:07:13PM +0200, Steffen Liebergeld wrote: > > >> According to documentation [0] the correct offset for the > > >> Upstream Peer Decode Configuration Register (UPDCR) is 0x1014. > > >> It was previously defined as 0x1114. This patch fixes it. > > >> > > >> [0] > > >> https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/4th-gen-core-family-mobile-i-o-datasheet.pdf > > >> (page 325) > > >> > > >> Signed-off-by: Steffen Liebergeld <steffen.liebergeld@xxxxxxxxxxxxxxx> > > > > > > You may also like to add: > > > > > > Fixes: d99321b63b1f ("PCI: Enable quirks for PCIe ACS on Intel PCH root ports") > > > Reviewed-by: Andrew Murray <andrew.murray@xxxxxxx> > > > > > > As well as CC'ing stable. > > > > Ok. Thank you. > > > > > I guess the side effect of this bug is that we claim to have peer > > > isolation when we do not. This fix ensures that we get the advertised > > > isolation. > > Yes, that is also my understanding. Should I explain that in the commit > > message? > > I think something similar to that would be helpful. This is unfortunate, but my initial impression is that this may have just been a typo that slipped by everyone. It's difficult to actually test for isolation. Maybe someone from Intel could review this. Also, Steffen discussed this with me prior to posting and I believe this is untested, so while trivial from inspection, it would be preferable to know that some sample of hardware doesn't fall over as a result. Thanks, Alex
