Re: [PATCH] PCI: remove unnecessary check of device_type == pci

From: Rob Herring
Date: Tue Sep 18 2018 - 15:05:55 EST


On Thu, Sep 13, 2018 at 7:51 AM Lorenzo Pieralisi
<lorenzo.pieralisi@xxxxxxx> wrote:
>
> On Wed, Aug 29, 2018 at 01:34:40PM -0500, Rob Herring wrote:
> > PCI host drivers have already matched on compatible strings, so checking
> > device_type is redundant. Also, device_type is considered deprecated for
> > FDT though we've still been requiring it for PCI hosts as it is useful
> > for finding PCI buses.
>
> Hi Rob,
>
> I have no problem with the patch per-se, I can't parse though the second
> paragraph, in particular what you mean by "useful for finding PCI
> buses".

Device_type is the only generic way we can identify PCI buses which is
useful for dtc for example to do PCI binding checks. Maybe we can use
the node name which is what I'm doing for cpu nodes, but we've been
less consistent about that for PCI.

>
> What about the corresponding dts files ? I suspect we had better leave
> them alone lest we can trigger regressions with new dts and older
> kernels.

Yes. it will take some time before we can remove from dts files. Or
maybe only new ones change.

Rob