Sat, Nov 09, 2019 at 09:46:59AM CET, gregkh@xxxxxxxxxxxxxxxxxxx wrote: >On Fri, Nov 08, 2019 at 08:44:26PM -0400, Jason Gunthorpe wrote: >> There has been some lack of clarity on what the ?? should be. People >> have proposed platform and MFD, and those seem to be no-goes. So, it >> looks like ?? will be a mlx5_driver on a mlx5_bus, and Intel will use >> an ice_driver on a ice_bus, ditto for cxgb4, if I understand Greg's >> guidance. > >Yes, that is the only way it can work because you really are just >sharing a single PCI device in a vendor-specific way, and they all need >to get along with each one properly for that vendor-specific way. So >each vendor needs its own "bus" to be able to work out things properly, >I doubt you can make this more generic than that easily. > >> Though I'm wondering if we should have a 'multi_subsystem_device' that >> was really just about passing a 'void *core_handle' from the 'core' >> (ie the bus) to the driver (ie RDMA, netdev, etc). > >Ick, no. > >> It seems weakly defined, but also exactly what every driver doing this >> needs.. It is basically what this series is abusing mdev to accomplish. > >What is so hard about writing a bus? Last I tried it was just a few >hundred lines of code, if that. I know it's not the easiest in places, >but we have loads of examples to crib from. If you have >problems/questions, just ask! > >Or, worst case, you just do what I asked in this thread somewhere, and >write a "virtual bus" where you just create devices and bind them to the >driver before registering and away you go. No auto-loading needed (or >possible), but then you have a generic layer that everyone can use if >they want to (but you loose some functionality at the expense of >generic code.) Pardon my ignorance, just to be clear: You suggest to have one-virtual-bus-per-driver or rather some common "xbus" to serve this purpose for all of them, right? If so, isn't that a bit ugly to have a bus in every driver? I wonder if there can be some abstraction found. > >Are these constant long email threads a way that people are just trying >to get me to do this work for them? Because if it is, it's working... Maybe they are just confused, like I am :) > >thanks, > >greg k-h
