On Fri, Aug 15, 2014 at 11:30:52AM +0100, Liviu Dudau wrote: > On Fri, Aug 15, 2014 at 09:56:32AM +0100, Wei Yang wrote: > > On Thu, Aug 14, 2014 at 04:49:59PM +0100, Liviu Dudau wrote: > > >On Thu, Aug 14, 2014 at 03:58:04PM +0100, Wei Yang wrote: > > >> On Tue, Aug 12, 2014 at 05:25:15PM +0100, Liviu Dudau wrote: > > >> > int __weak pcibios_add_device(struct pci_dev *dev) > > >> > { > > >> >+ dev->irq = of_irq_parse_and_map_pci(dev, 0, 0); > > >> >+ > > >> > return 0; > > >> > } > > >> > > >> For this, my suggestion is to add arch dependent function to setup the > > >> irq > > >> line for pci devices. I can't find an obvious reason this won't work on > > >> other > > >> archs, but maybe this will hurt some of them? > > > > > >I'm not sure I understand your point. Architectures that support OF will > > >obviously > > >benefit from this common approach, and for the other ones the function is > > >empty > > >so it will not change existing behaviour. If you are suggesting that I > > >should > > >create a new API that each architecture could go and implement for setting > > >up the > > >IRQ line then I would agree that it would be nice to have that, but the > > >question > > >is how many architectures are outside OF that need this? > > > > My suggestion is to define the pcibios_add_device() for arm arch, like the > > one > > in arch/powerpc/kernel/pci-common.c. If my understanding is correct, this > > patch set address the pci bus setup mostly on arm arch. > > And also arm64 at the least. ... > Well, it will become necessary as old code gets dismantled and converted > towards > this patchset. To give you an example that I'm familiar with, for arch/arm the > host bridge drivers have moved into drivers/pci/host, but they still > depend/use > the bios32 infrastructure that takes care of setting up the irq. When they > switch > to my version they would have to go and debug the "irq not being assigned" > issue > and it is quite likely that some of the people doing the conversion will > complain > about my code rather than understanding the issue. What I'm trying to do is to > make switching to my patchset as painless as possible, with a cleanup to > remove > redundant operations coming after the switchover.
While the goal is fine, until we see a common pattern for what needs to go into pcibios_add_device() I think we should have an arm64-specific implementation (and probably an arm32 specific one as well). I can see powerpc uses it for setting the DMA ops. Would we have a similar need on arm64 to choose between coherent and non-coherent dma_ops? Also at some point we'll get ACPI support, so I'm not sure what we do with assigning the dev->irq here but definitely of_* functions won't work. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/