# Re: \[PATCH V8\] powerpc/fsl-pci: Unify pci/pcie initialization code

- From: Li Yang-R58472 \<hidden\>
- Date: 2012-08-21 18:09:39 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2012/08/9470875
- Thread: https://ratatoskr.run/linuxppc-dev/2012/08/9470853/t.md

```text


On Aug 22, 2012, at 1:16, "Wood Scott-B07421" [ref] wrote:

> On 08/21/2012 01:49 AM, Li Yang-R58472 wrote:
>> If there is i8259 node in the device tree, it should be suggesting
>> that there is a PCI to ISA bridge but not explicitly described in the
>> device tree.  Then we need to fix the device tree to add the ISA
>> nodes.
>=20
> No, we need to work with existing device trees.  Just because they're
> hosted in the kernel tree doesn't mean they can be treated as an
> internal kernel implementation detail.  They are stable API with
> external entities such as bootloaders and hypervisors, get forked for
> custom boards, etc.

You are right that device tree binding is a stable API but not a poorly wri=
tten dts instance.  We are not changing any binding definition.  It is just=
 adding the somehow missed node that should be there in some poorly written=
 dts in the first place according to current binding.  Is it making any sen=
se to have ISA devices directly under pci bus?


>=20
> Boards with this problem should set fsl_pci_primary in platform code
> based on whatever criteria is relevant.

I don't know how legitimate it is to use a new kernel but not the device tr=
ee from that source.  If that's the problem that we need to take care of, I=
 think we need to add the workaround in the platform code temporarily for a=
 transitional period.

>=20
> -Scott
>=20
```