[PATCH V4 3/3] powerpc/fsl-pci: Unify pci/pcie initialization code

[Jia Hongtao-B38951]

> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Wednesday, August 08, 2012 11:54 PM
> To: Jia Hongtao-B38951
> Cc: Wood Scott-B07421; Kumar Gala; linuxppc-dev at lists.ozlabs.org; Li
> Yang-R58472
> Subject: Re: [PATCH V4 3/3] powerpc/fsl-pci: Unify pci/pcie
> initialization code
> 
> On 08/07/2012 10:57 PM, Jia Hongtao-B38951 wrote:
> >
> >
> >> -----Original Message-----
> >> From: Wood Scott-B07421
> >> Sent: Tuesday, August 07, 2012 11:20 PM
> >> To: Jia Hongtao-B38951
> >> Cc: Wood Scott-B07421; Kumar Gala; linuxppc-dev at lists.ozlabs.org; Li
> >> Yang-R58472
> >> Subject: Re: [PATCH V4 3/3] powerpc/fsl-pci: Unify pci/pcie
> >> initialization code
> >>
> >> On 08/07/2012 01:23 AM, Jia Hongtao-B38951 wrote:
> >>>> -----Original Message-----
> >>>> From: Wood Scott-B07421
> >>>> Sent: Monday, August 06, 2012 11:16 PM
> >>>> To: Jia Hongtao-B38951
> >>>> Cc: Wood Scott-B07421; Kumar Gala; linuxppc-dev at lists.ozlabs.org;
> >>>> Li
> >>>> Yang-R58472
> >>>> Subject: Re: [PATCH V4 3/3] powerpc/fsl-pci: Unify pci/pcie
> >>>> initialization code
> >>>>
> >>>> On 08/05/2012 09:39 PM, Jia Hongtao-B38951 wrote:
> >>>>>
> >>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: Wood Scott-B07421
> >>>>>> Sent: Saturday, August 04, 2012 12:04 AM
> >>>>>> To: Jia Hongtao-B38951
> >>>>>> Cc: Kumar Gala; linuxppc-dev at lists.ozlabs.org; Wood Scott-B07421;
> >>>>>> Li
> >>>>>> Yang-R58472
> >>>>>> Subject: Re: [PATCH V4 3/3] powerpc/fsl-pci: Unify pci/pcie
> >>>>>> initialization code
> >>>>>>
> >>>>>> On 08/02/2012 10:39 PM, Jia Hongtao-B38951 wrote:
> >>>>>>>
> >>>>>>>
> >>>>>>>> -----Original Message-----
> >>>>>>>> From: Kumar Gala [mailto:galak at kernel.crashing.org]
> >>>>>>>> Sent: Thursday, August 02, 2012 8:24 PM
> >>>>>>>> To: Jia Hongtao-B38951
> >>>>>>>> Cc: linuxppc-dev at lists.ozlabs.org; Wood Scott-B07421; Li
> >>>>>>>> Yang-R58472
> >>>>>>>> Subject: Re: [PATCH V4 3/3] powerpc/fsl-pci: Unify pci/pcie
> >>>>>>>> initialization code
> >>>>>>>>
> >>>>>>>> You need to convert all boards to use fsl_pci_init before this
> >> patch.
> >>>>>>>> Otherwise we'll end up with PCI getting initialized twice on
> >> boards.
> >>>>>>>>
> >>>>>>>> - k
> >>>>>>>
> >>>>>>> If we covert all boards with platform driver in this patch PCI
> >>>>>>> will be initialized only once without converting all boards to
> >>>>>>> use fsl_pci_init first.
> >>>>>>
> >>>>>> Then we'd have to pick apart core changes from board changes when
> >>>>>> reviewing.
> >>>>>>
> >>>>>>> If we convert all boards to use fsl_pci_init before this patch
> >>>>>>> and convert them to use platform driver again after this patch.
> >>>>>>> Then between this patch and next pci will be initialized twice
> too.
> >>>>>>
> >>>>>> Why?  That one patch should both create the platform driver and
> >>>>>> remove the init from fsl_pci_init() -- except things like primary
> >> bus
> >>>>>> detection which has to happen globally.
> >>>>>>
> >>>>>> -Scott
> >>>>>
> >>>>> "One patch both create the platform driver and remove the init
> >>>>> from fsl_pci_init()" means we should create platform driver and
> >>>>> applied to all boards. If so why not just directly convert all
> >>>>> boards using platform driver?
> >>>>
> >>>> Because it's harder to review when you have a bunch of board code
> >>>> in
> >> the
> >>>> patch in addition to core changes.
> >>>>
> >>>> Because you might want people to actually test on the boards in
> >> question
> >>>> when converting, especially given the change in how primary buses
> >>>> are determined, and that some boards may need to provide their own
> >>>> alternative.
> >>>>
> >>>> -Scott
> >>>
> >>> But if we separate the core changes and the boards update, between
> >>> this
> >> two
> >>> patches PCI will be initialized twice.
> >>
> >> As I said earlier, you can remove the initcall and require boards to
> >> manually call fsl_pci_init() until all boards are converted.
> >>
> >> -Scott
> >
> > As I said earlier, I can do this but it does not solve the twice-init
> problem.
> 
> I must have missed it.  Why does it not solve the problem?  If a board
> doesn't call fsl_pci_init(), the platform driver doesn't get registered.
> 
> > If I do this first and then add platform driver we also have to
> > convert all boards using platform driver in the same patch.
> >
> > We finally using the platform driver so Why do you keep insisting on
> > converting all boards using fsl_pci_init() first even it does no
> improvement.
> 
> What we're asking for is bisectability (don't have any intermediate
> stages where PCI gets initialized twice), and the ability to have a
> smooth transition where boards can be converted as people are able to
> test them and look into their individual needs regarding primary bus.
> 
> -Scott

In my patch there is no bisectability problem. If you don't think so could
you please give more details?

-Hongtao.