Re: [PATCH 3/6] PCI: Introduce devm_of_pci_get_host_bridge_resources

[Bjorn Helgaas]

On Sat, Apr 28, 2018 at 09:28:47AM +0200, Jan Kiszka wrote:
> On 2018-04-28 00:24, Bjorn Helgaas wrote:
> > On Tue, Apr 24, 2018 at 05:13:39PM +0200, Jan Kiszka wrote:
> >> From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> >>
> >> of_pci_get_host_bridge_resources allocates the resource structures it
> >> fills dynamically, but none of its callers care to release them so far.
> >> Rather than requiring everyone to do this explicitly, introduce a
> >> managed version of that service. This differs API-wise only in taking a
> >> reference to the associated device, rather than to the device tree node.
> >>
> >> As of_pci_get_host_bridge_resources is an exported interface, we cannot
> >> simply drop it at this point. After converting all in-tree users to the
> >> new API, we could phase out the unmanaged one over some grace period.
> > 
> > It looks like it might be possible to split this into three or four
> > patches:
> > 
> >   1) Factor __of_pci_get_host_bridge_resources() out of
> >      of_pci_get_host_bridge_resources()
> > 
> >   2) Add struct device * argument
> > 
> >   3) Convert pr_info() to dev_info()
> > 
> >   4) Add devm_of_pci_get_host_bridge_resources()
> 
> Will do. I'm even considering
> 
> 5) mark of_pci_get_host_bridge_resources() __deprecated, due to the leak
>    and no remaining in-tree user - what do you think?

Sounds good.

It'd be nice if we had some guideline about deprecation -- whether we
actually need to mark things __deprecated, and then how long to wait
before actually removing them, but I don't see anything in
Documentation/.

Looks like it was added by cbe4097f8ae6 ("of/pci: Add support for
parsing PCI host bridge resources from DT") in v3.18, so it's been
around for a while and I guess it would be nice to have a grace period
before removing it.