On Jul 31, 2012, at 2:21 AM, Li Yang wrote: > On Mon, Jul 30, 2012 at 10:46 PM, Kumar Gala <ga...@kernel.crashing.org> > wrote: >> >> On Jul 30, 2012, at 3:26 AM, Jia Hongtao-B38951 wrote: >> >>> >>> >>>> -----Original Message----- >>>> From: Kumar Gala [mailto:ga...@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; >>>> 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: >>>> >>>>> On 07/27/2012 05:10 AM, Jia Hongtao-B38951 wrote: >>>>>> 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. >>>>> >>>>> Another possibility is to try to handle swiotlb init later -- possibly >>>>> by reserving memory for it if the platform indicates it's a possibility >>>>> 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() >>>> as we now have it and just have the platform driver deal with PM restore >>>> via calling setup_pci_atmu() [probably need to update setup_pci_atmu to >>>> 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 >>> advantage. I really like to keep the completion of pci controller >>> platform driver not only for PM support but also for pci init. >>> >>> -Hongtao. >>> >> >> Shifting of swiotlb init has a lot more issues. Why do we need to do the >> PCI init in probe? > > The ordering issues are introduced by swiotlb. And the ideal way is > to solve the problem within swiotlb instead of changing PCI to > workaround it. Take the implementation of x86 as reference it's > possible to be addressed bu allocating first and free later approach. > > It is common sense that the initialization of a device is in the probe > function of the driver of the device. And the change will provide > better unification of PCI controller code. The PCI controller is > generic enough not to be taken care of at the platform area. > > Leo
Than lets look at going with that approach.. Be careful with impact on other users of swiotlb on PPC, I believe one 44x board uses swiotlb. - k _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
