On Aug 22, 2012, at 1:16, "Wood Scott-B07421" [off-list ref] wrote:
On 08/21/2012 01:49 AM, Li Yang-R58472 wrote:
quoted
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