Re: [PATCH v3 1/2] PCI: generic: remove dependency on hw_pci

[Will Deacon <will.deacon@arm.com>]

Hi Jayachandran, Bjorn,

On Fri, Jul 31, 2015 at 05:27:16PM +0100, Lorenzo Pieralisi wrote:
> On Fri, Jul 31, 2015 at 05:07:01PM +0100, Jayachandran C. wrote:
> > On Thu, Jul 30, 2015 at 02:35:21PM +0100, Lorenzo Pieralisi wrote:
> > > On Wed, Jul 29, 2015 at 04:28:00PM +0100, Jayachandran C wrote:
> > > > -	pci_common_init_dev(dev, &hw);
> > > > +	/* do not reassign resource if probe only */
> > > > +	if (!pci_has_flag(PCI_PROBE_ONLY))
> > > > +		pci_add_flags(PCI_REASSIGN_ALL_RSRC);
> > > 
> > > You should add PCI_REASSIGN_ALL_BUS here. As I said in patch 2 comment,
> > 
> > The idea is to do exactly what pci_common_init_dev does on ARM. There is
> > not need to change behavior on ARM and deal with the fallout in this
> > patchset.
> 
> You are enabling this driver on ARM64, and on ARM64 that flag does
> make a difference, it does not on ARM as far as I can tell, but you do
> not seem to care.
> 
> Actually Rob asked you to put together a function since most of
> this code is replicated across ARM drivers eg:
> 
> drivers/pci/host/pci-versatile.c
> 
> Leave the code as it is and I will consolidate the code later.
> 
> > > please enable setup-irq.c in an explicit commit, re-sequence the
> > > series and fold the Kconfig ARM64 enablement in this patch.
> > 
> > I would think that the Makefile and Kconfig changes should be
> > togethter as the arm64 enablement patch. The previous patch is
> > to update the gen_pci driver, and it really makes sense in that
> > order.  I am not sure why you suggest this change.
> 
> Because this is not the only driver that requires compiling
> drivers/pci/setup-irq.c on ARM64, I thought it made more sense
> to do it in a separate patch to make that change standalone.
> 
> If for any reason we have to revert your patch that enables
> PCI host generic on ARM64 (and we remove with it the compilation
> of setup-irq.c) we would break other ARM64 PCI hosts that require it,
> right ?
> 
> I leave the decision to Bjorn since I am away next week, I am fine
> with the code as it is so please go ahead.

In the interest of getting something merged, can I suggest you
(Jayachandran) repost the patches with Lorenzo's suggestions to reorder
the series and split up the setup-irq compilation into a separate patch?

You can also add his ack to this patch.

It's a pity that the code isn't quite how we'd like it to end up, but
this at least enables people for 4.3 and I know that Lorenzo is working
on tidying up the loose ends as additional patches (but he's on holiday
this week). That includes removal of the PROBE_ONLY bodge that I've got
queued in arch/arm64/kernel/pci.c.

Bjorn, does that sound ok to you? I'm keen to have something working, as
I'm starting to get beaten up about the lack of generic PCI on arm64.

Cheers,

Will