RE: [PATCH V5 1/1] NTB: Add support for AMD PCI-Express Non-Transparent Bridge

From: Allen Hubbe
Date: Thu Jan 21 2016 - 01:17:26 EST

From: Yu, Xiangliang [mailto:Xiangliang.Yu@xxxxxxx]
> > > Signed-off-by: Jon Mason <jdmason@xxxxxxxx>
> > > Signed-off-by: Allen Hubbe <Allen.Hubbe@xxxxxxx>
> >
> > NO.
> Ok, I'll change it if you doesn't want to change it.

Nah, just remember it for next time...

I'm satisfied with this v5.

Reviewed-by: Allen Hubbe <Allen.Hubbe@xxxxxxx>

> I donât think so. In here, the i/o memory is only happened when
> pci_iomap return
> Success, so the register can't be accessed through IO port way. And
> ioread* will
> Check if the memory type is mmio type or IO port type (please see the
> definition).
> I donât think we need to check It, so I use read* because It can make
> more efficient.
> I think we need to think about actual usage, not only follow book.
> And, I have said it in previous version, I donât like explain it again,
> and again.
> If you have any concern, please tell me after my comment.

It's not more efficient, on this platform it's the same.

If it were my driver I would change it... but you can keep it this way.

> > This is different from v4. It used to be:
> Because peer_sta is change to 0, so amd_link_is_up will return 0
> (offline)
> And will not check hardware link status. So It maybe make it offline
> forever

It fixed a bug? Great!

> > I'm nervous about ndev->peer_sta, the behavior of link_is_up,
> > timers...
> Actually, the code is designed according to Atom NTB, except for the
> peer_sta.

Except for peer_sta, and that's a pretty critical design change. I'm still nervous, but I'll trust that you have been able to test this behavior thourougly.

> I'll add the explaination when having changes.