Re: linux-next: manual merge of the devicetree tree with the powerpc tree

On Wed, 2012-03-14 at 09:53 +0800, Gavin Shan wrote:

quoted

 +#if defined(CONFIG_EEH)

quoted

 +static inline struct eeh_dev *of_node_to_eeh_dev(struct device_node *dn)
 +{
 +  return dn->edev;
 +}
 +#endif

Ben, What is this?  I don't want the eeh_dev pointer in struct device_node.  Up to
now we've avoided putting any reverse references into device_nodes.  For everything
else we use a reverse lookup, particularly for devices, to avoid growing the
device_node for each new type of lookup.

It's used to trace the EEH device. When EEH (Enhanced Error Hanlding) is enabled,
EEH device will be created against PCI sensitive OF node to trace the EEH state
accordingly. Since you don't want see this in struct device_node, we have to change
struct eeh_dev for a little bit to so that all struct eeh_dev instances will form
a global list and we can search eeh_dev according to the given device_node through
the global list. 

I don't know the policy or rule here for much. I think we can have 2 options.

1. Keep the code as being, and fix it later.
2. Fix it now. 

My bad, it's a mis-review, I thought it was still in pci_dn, I din't
catch Gavin moving it to device-node.

Yes, Gavin, we need to do something else, a chained list we walk or
something like that. For the "fast path" which is when we have a pci_dev
around, we can either add it to dev_archdata or hijack the pci-dev
platform_data (I don't think anything uses it, Grant, do you know of
anything ?)

The patches are already in -next and I won't rebase, so we need to fix
it on top of the existing patches. Gavin, can you make a patch that puts
it back into pci_dn to begin with, then we can contemplate what better
long term solution we have ?

Cheers,
Ben.