[PATCH 0/3] powerpc/fsl: PCI refactoring and QEMU paravirt platform

[Li Yang-R58472]

> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Friday, June 29, 2012 11:02 AM
> To: Kumar Gala
> Cc: Jia Hongtao-B38951; Wood Scott-B07421; Li Yang-R58472; agraf at suse.de;
> linuxppc-dev at lists.ozlabs.org
> Subject: Re: [PATCH 0/3] powerpc/fsl: PCI refactoring and QEMU paravirt
> platform
> 
> On 06/29/2012 10:57 AM, Kumar Gala wrote:
> >
> > On Jun 28, 2012, at 9:36 PM, Jia Hongtao-B38951 wrote:
> >
> >>
> >>
> >>> -----Original Message-----
> >>> From: Wood Scott-B07421
> >>> Sent: Friday, June 29, 2012 12:31 AM
> >>> To: Jia Hongtao-B38951
> >>> Cc: Wood Scott-B07421; galak at kernel.crashing.org; Li Yang-R58472;
> >>> agraf at suse.de; linuxppc-dev at lists.ozlabs.org
> >>> Subject: Re: [PATCH 0/3] powerpc/fsl: PCI refactoring and QEMU
> >>> paravirt platform
> >>>
> >>> On 06/27/2012 11:06 PM, Jia Hongtao-B38951 wrote:
> >>>>
> >>>>
> >>>>> -----Original Message-----
> >>>>> From: Wood Scott-B07421
> >>>>> Sent: Thursday, June 28, 2012 7:49 AM
> >>>>> To: galak at kernel.crashing.org
> >>>>> Cc: agraf at suse.de; linuxppc-dev at lists.ozlabs.org; Jia
> >>>>> Hongtao-B38951
> >>>>> Subject: [PATCH 0/3] powerpc/fsl: PCI refactoring and QEMU
> >>>>> paravirt platform
> >>>>>
> >>>>> The QEMU stuff is related to the PCI refactoring because currently
> >>>>> we have a hard time selecting a primary bus under QEMU, and also
> >>> because
> >>>>> the generic qemu e500 platform wants a full list of FSL PCI
> >>> compatibles
> >>>>> to check.
> >>>>>
> >>>>
> >>>> It seems that not all primary bus has "isa" node like 8541 and 8555.
> >>>
> >>> Do those boards (it's the boards that matter, not chips...) have
> >>> legacy ISA?  If they do, and it's not in the device tree, then we
> >>> should fix the device tree for consistency, but also retain some
> >>> sort of hack to remain compatible with old device trees.
> >>>
> >>> A board can refrain from using the new common infrastructure if it
> >>> has a good reason to.
> >>
> >> I'm not sure that MPC8541CDS (or 8555) has legacy ISA. I just checked
> >> in kernel and dts which implies the board has primary bus and no "isa"
> node.
> >> I will find out the facts later.
> >
> > Pretty sure the boards have ISA, if you see the .dts has references to
> 'ISA bridge' & 'i8259' PIC.
> 
> OK.  How about looking for an i8259 node as well?

That could work, but looks hackish.  Our proposal for adding a new device tree property is a generic solution.  The only problem is that new kernels would work with old device trees.  I think we can use your solution for transitional period.  And go for a well defined device tree binding for this in long run.

- Leo