On Tue, Mar 22, 2016 at 5:19 AM, Bruce Richardson < bruce.richardson at intel.com> wrote:
> On Tue, Mar 22, 2016 at 05:50:28AM +0000, Qiu, Michael wrote: > > > > Why not to implement one simple API with variable arguments, just like > > syscall ioctl() does. And drivers implement it's specific hardware > > features with a feature bit param, and other needed variable arguments. > > > > Thanks, > > Michael > > A very much dislike that idea. > * It makes the code much harder to read as you have to closely examine all > the > parameters to work out what a function call is actually meant to do. > * It makes it much harder to see that you have an implicit dependency on a > specific device. Having to include a driver specific header file e.g. > i40e.h, > and call a function named e.g. i40e_do_magic_stuff(), makes it pretty > explicit > that you have a dependency on i40e-based hardware > * It prevents the compiler from doing type-checking on parameters and > informing > you of little inconsistencies. > > For all these reasons, I prefer the device-specific functions option. > However, > at the same time, we also need to ensure we have a reasonable set of > generic > APIs so that the cases where users are forced to drop down to the > lower-level > device-specific primitives are reduced. > +1 Jay
