RE: [PATCH V3 1/5] powerpc/fsl-pci: Unify pci/pcie initialization code

-----Original Message-----
From: Kumar Gala [mailto:galak@kernel.crashing.org]
Sent: Monday, July 30, 2012 10:47 PM
To: Jia Hongtao-B38951
Cc: Wood Scott-B07421; linuxppc-dev@lists.ozlabs.org; Li Yang-R58472
Subject: Re: [PATCH V3 1/5] powerpc/fsl-pci: Unify pci/pcie
initialization code
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On Jul 30, 2012, at 3:26 AM, Jia Hongtao-B38951 wrote:
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-----Original Message-----
From: Kumar Gala [mailto:galak@kernel.crashing.org]
Sent: Saturday, July 28, 2012 5:17 AM
To: Wood Scott-B07421
Cc: Jia Hongtao-B38951; linuxppc-dev@lists.ozlabs.org; Wood Scott-

B07421;

quoted

quoted

Li Yang-R58472
Subject: Re: [PATCH V3 1/5] powerpc/fsl-pci: Unify pci/pcie
initialization code


On Jul 27, 2012, at 3:24 PM, Scott Wood wrote:

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On 07/27/2012 05:10 AM, Jia Hongtao-B38951 wrote:

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Hi kumar,

I know "duplicate code from pci_process_bridge_OF_ranges()" is
hard to accept but "refactor the code to have a shared function"
is knotty. Actually this is the reason I didn't do the refactor.

Maybe we should keep doing the init early?  We could still have a
platform device for the PM stuff, but some init would be done before

probe.

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Another possibility is to try to handle swiotlb init later --

possibly

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by reserving memory for it if the platform indicates it's a

possibility

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that it will be needed, then freeing the memory if it's not needed.

-Scott

I think the first option seems reasonable.  Can we leave fsl_pci_init(=

)

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as we now have it and just have the platform driver deal with PM

restore

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via calling setup_pci_atmu() [probably need to update setup_pci_atmu

to

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handle restore case, but seems like minor changes]

- k

I think the second option is better if it's hard to decouple swiotlb
determination from pci init. I believe the better architecture that
PCI init in probe function of platform driver will bring us

considerable

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advantage. I really like to keep the completion of pci controller
platform driver not only for PM support but also for pci init.

-Hongtao.

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Shifting of swiotlb init has a lot more issues.  Why do we need to do the
PCI init in probe?
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- k

I investigated the swiotlb init thing and found that in x86 swiotlb init is
done first and free if we don't need it.

-Hongtao.