On Monday 10 March 2014 14:44:14 Liviu Dudau wrote: > I will try to improve the error handling in the next patchset version. > However I am still confused about the earlier discussion on > pci_register_io_range(). Your suggestion initially was to return an > error in the default weak implementation, but in your last email you > are talking about returning 'port'. You can do either one: 'port' should be positive or zero, while the error would always be negative. We do the same thing in many interfaces in the kernel. > My idea when I've introduced the > helper function was that it would return an error if it fails to > register the IO range and zero otherwise. I agree that we can treat > the default 'do nothing with the IO range' case as an error, with > the caveat that will force architectures that use this code to > provide their own implementation of pci_register_io_range() in order > to avoid failure, even for the cases where the architecture has a 1:1 > mapping between IO and CPU addresses. Which architectures are you thinking of? The only one I know that does this is ia64, and we won't ever have to support this helper on that architecture. I did not ask to treat 'do nothing with the IO range' as an error, what I meant is that we should treat 'architecture cannot translate from I/O space to memory space but DT lists a translation anyway' as an error. On x86, you should never see an entry for the I/O space in "ranges", so we will not call this function unless there is a bug in DT. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
