On 08/08/2012 10:48 PM, Jia Hongtao-B38951 wrote: > > >> -----Original Message----- >> From: Wood Scott-B07421 >> Sent: Wednesday, August 08, 2012 11:58 PM >> To: Jia Hongtao-B38951 >> Cc: Wood Scott-B07421; Li Yang-R58472; linuxppc-dev@lists.ozlabs.org; >> Gala Kumar-B11780 >> Subject: Re: [PATCH V5 3/3] powerpc/fsl-pci: Unify pci/pcie >> initialization code >> >> On 08/08/2012 04:03 AM, Jia Hongtao-B38951 wrote: >>> >>> >>>> -----Original Message----- >>>> From: Wood Scott-B07421 >>>> Sent: Tuesday, August 07, 2012 11:25 PM >>>> To: Li Yang-R58472 >>>> Cc: Wood Scott-B07421; linuxppc-dev@lists.ozlabs.org; Li Yang-R58472; >>>> Jia >>>> Hongtao-B38951 >>>> Subject: Re: [PATCH V5 3/3] powerpc/fsl-pci: Unify pci/pcie >>>> initialization code >>>> >>>> On 08/06/2012 11:20 PM, Li Yang wrote: >>>>> On Mon, Aug 6, 2012 at 11:09 PM, Scott Wood >>>>> <scottw...@freescale.com> >>>> wrote: >>>>>> On 08/05/2012 10:07 PM, Jia Hongtao-B38951 wrote: >>>>>>> >>>>>>> >>>>>>>> -----Original Message----- >>>>>>>> From: Wood Scott-B07421 >>>>>>>> Sent: Saturday, August 04, 2012 12:28 AM >>>>>>>> To: Jia Hongtao-B38951 >>>>>>>> Cc: linuxppc-dev@lists.ozlabs.org; ga...@kernel.crashing.org; Li >>>>>>>> Yang- R58472; Wood Scott-B07421 >>>>>>>> Subject: Re: [PATCH V5 3/3] powerpc/fsl-pci: Unify pci/pcie >>>>>>>> initialization code >>>>>>>> >>>>>>>> As I explained before, this has to be done globally, not from the >>>>>>>> probe function, so we can assign a default primary bus if there >>>> isn't any ISA. >>>>>>>> There are bugs in the Linux PPC PCI code relating to not having >>>>>>>> any primary bus. >>>>>>>> >>>>>>>> -Scott >>>>>>> >>>>>>> In my way of searching ISA you can also assign a default primary >>>>>>> bus in board specific files. >>>>>> >>>>>> That was meant for when the board file had an alternate way of >>>>>> searching for the primary bus (e.g. look for i8259), not as a >>>>>> replacement for the mechanism that guarantees there's a primary bus. >>>>>> >>>>>> You are causing a regression in the qemu_e500.c platform. >>>>> >>>>> Can we fix the qemu device tree to address the problem if we do make >>>>> it a rule to use the ISA node to indicate the primary bus? >>>> >>>> No. There is no ISA, and we're not going to lie and say there is. >>> >>> But we can assign a default primary for qemu. >> >> Not in the device tree. What other mechanism do you propose? And why do >> you want to fix it only for QEMU and not other boards, where things >> happen to work but not as designed? >> >> Kumar, can you speak up here as maintainer so we can stop going back and >> forth endlessly? >> >>>> I really don't understand what the problem is with leaving the >>>> primary detection code as global. Either fix the bugs so we don't >>>> need a primary, or accept some "impurity" in the workaround. >>>> >>>> -Scott >>> >>> Global detection for primary is ok but we think our way is deeper >> unified. >> >> So my way works and "is ok", and your way doesn't work but is >> theoretically cleaner. > > Sorry, I meant global detection is ok but I didn't mean that your logic > is ok. The concern is in some cases there is no isa node in device tree > and the primary is not the first bus. Your logic assigned a wrong primary > there. Is that a problem? Take ge_imp3a as an example. > > So maybe we should fix this exceptional board.
Boards like that are why the code first checks for whether fsl_pci_primary is NULL. Board code can set fsl_pci_primary based on other criteria before calling fsl_pci_init(). This is why we need to allow for a gradual conversion, so boards like that can get personal attention by someone who can test the change. -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
