Re: [edk2-platforms][PATCH v2 16/32] AmpereAltraPkg: Add PciHostBridge driver

["Ard Biesheuvel" <ardb@kernel.org>]

On Tue, 15 Jun 2021 at 17:54, Nhi Pham <nhi@os.amperecomputing.com> wrote:
>
> On 6/9/21 12:29, Ard Biesheuvel wrote:
> > On Wed, 26 May 2021 at 12:12, Nhi Pham <nhi@os.amperecomputing.com> wrote:
> >> From: Vu Nguyen <vunguyen@os.amperecomputing.com>
> >>
> >> The roles of this driver:
> >> * Consume PcieCoreLib to initialize all enable PCIe controllers.
> >> * Produce neccessary protocols like RootBridgeIo an ResourceAllocation
> >>    which will be used later by PciBus.
> >>
> >> Cc: Thang Nguyen <thang@os.amperecomputing.com>
> >> Cc: Chuong Tran <chuong@os.amperecomputing.com>
> >> Cc: Phong Vo <phong@os.amperecomputing.com>
> >> Cc: Leif Lindholm <leif@nuviainc.com>
> >> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> >> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> >> Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
> >>
> >> Signed-off-by: Vu Nguyen <vunguyen@os.amperecomputing.com>
> > Why do you need a re-implementation of PciHostBridgeDxe for any of
> > this? There is very little h/w specific code there, and it is all
> > customizable using PciHostBridgeLib and PciSegmentLib (among others)
> >
> > There are a couple of examples of this in edk2-platforms - please take
> > a look at those, and if that does not give you enough wiggle room,
> > let's see if we can accommodate your needs in PciHostBridgeDxe itself.
> >
> Hi Leif, Ard,
>
> Thanks for your comments. The current implementation which has little
> deltas comparing with the standard one has been well-tested. It's a good
> idea that we need to re-implement it based on Ard's suggestion, but it
> will take time and we need to make sure that it is well-tested
> internally before getting it out.

That is reasonable.

> So, we want to keep this current
> implementation but we will start looking at working the
> re-implementation in the future.
>

I would prefer to wait for this to happen, rather than merge 4000+
lines of code which are almost identical to the original, without any
agreement on when it can be removed again.

Thanks,
Ard.