Re: [PATCH v1 3/7] PCI: New Primary to Sideband (P2SB) bridge support library

Henning Schild
2021-04-06T13:44:44Z

Am Fri, 2 Apr 2021 15:09:12 +0200
schrieb "Enrico Weigelt, metux IT consult" <lkml@metux.net>:

> On 09.03.21 09:42, Henning Schild wrote:
>
> > The device will respond to MMIO while being hidden. I am afraid
> > nothing stops a collision, except for the assumption that the BIOS
> > is always right and PCI devices never get remapped. But just
> > guessing here.
>
> What could go wrong if it is remapped, except that this driver would
> write to the wrong mmio space ?
>
> If it's unhidden, pci-core should see it and start the usual probing,
> right ?

I have seen this guy exposed to Linux on coreboot machines. No issues.
But i can imagine BIOSs that somehow make use of the device and assume
it wont move. So we would at least need a parameter to allow keeping
that device hidden, or "fixed" in memory.

Henning

>
> --mtx
>