On Mon, Aug 18, 2014 at 10:30:54PM +0100, Liviu Dudau wrote: > On Mon, Aug 18, 2014 at 03:25:50PM +0100, Catalin Marinas wrote: > > 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? > > At this point I would like to hear more from people doing the conversion of > the drivers. I cannot answer fully for all arm or arm64 drivers. As I read the description of pcibios_add_device(), it is meant as an architecture hook. While it's nice to generalise this, I'm not sure we we can find a common denominator. For example, we may want to call set_dma_ops() as powerpc does but the ops would be arm64 specific (so even the __weak implementation may not be used by any architecture). -- Catalin -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html