On 2 February 2017 at 16:37, Logan Gunthorpe <logang@xxxxxxxxxxxx> wrote: > > > On 01/02/17 05:10 AM, Emil Velikov wrote: >> You can keep it roughly as-is if you're ~reasonably certain one won't >> change it in the future. > > I've made the change anyway. I think it's better now. > >> Some teams frown upon adding new IOCTL(s) where existing ones can be >> made backward/forward compatible. >> I'm not fully aware of the general direction/consensus on the topic, >> so it might be a minority. > > Sure, I just don't know what might be needed in the future so it's hard > to add a version or flags ioctl now. > Yes knowing how things will need to change in the is hard. That's why the documentation suggestions adding a flag to the ioctl structs. It [the flag] might imply certain functional/implementation change, support for new/deprecation of old features and others. >> On the other hand, reading through sysfs for module version in order >> to use IOCTL A or B sounds quite hacky. Do you have an example where >> this is used or pointed out as good approach ? > > I don't know of anything doing it that way now. But it sure would be > easy and make a bit of sense. (We'd actually use the module version for > something useful.) Either way, it would really depend on if and how > things change in the future. The point is there are options to expand if > needed. > The part that nobody else is doing such a thing should ring a bell ;-) It's no my call, but if it was I'd stick with the existing approach and not "reinvent the wheel" sort of speak. Thanks Emil
