Re: [RFC 2/2] pci-expender-bus:Add pcie-root-port to pxb-pcie under arm.

[Daniel P . Berrangé]

On Fri, Feb 14, 2020 at 07:25:43AM +0000, miaoyubo wrote:
> 
> > -----Original Message-----
> > From: Daniel P. Berrangé [mailto:address@hidden]
> > Sent: Thursday, February 13, 2020 9:52 PM
> > To: miaoyubo <address@hidden>
> > Cc: address@hidden; address@hidden;
> > address@hidden; address@hidden; Xiexiangyou
> > <address@hidden>; address@hidden
> > Subject: Re: [RFC 2/2] pci-expender-bus:Add pcie-root-port to pxb-pcie
> > under arm.
> > 
> > On Thu, Feb 13, 2020 at 03:49:52PM +0800, Yubo Miao wrote:
> > > From: miaoyubo <address@hidden>
> > >
> > > Since devices could not directly plugged into pxb-pcie, under arm, one
> > > pcie-root port is plugged into pxb-pcie. Due to the bus for each
> > > pxb-pcie is defined as 2 in acpi dsdt tables(one for pxb-pcie, one for
> > > pcie-root-port), only one device could be plugged into one pxb-pcie.
> > 
> > What is the cause of this arm specific requirement for pxb-pcie and more
> > importantly can be fix it so that we don't need this patch ?
> > I think it is highly undesirable to have such a per-arch difference in
> > configuration of the pxb-pcie device. It means any mgmt app which already
> > supports pxb-pcie will be broken and need to special case arm.
> > 
> 
> Thanks for your reply, Without this patch, the pxb-pcie is also useable, 
> however, one extra pcie-root-port or pci-bridge or something else need 
> to be defined by mgmt. app. This patch will could be abandoned.

That's not really answering my question. IIUC, this pxb-pcie device
works fine on x86_64, and I want to know why it doesn't work on arm ?
Requiring different setups by the mgmt apps is not at all nice because
it will inevitably lead to broken arm setups. x86_64 gets far more testing
& usage, developers won't realize arm is different.



Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|