On Sun, Dec 06, 2020 at 05:58:32PM +0900, Blaž Hrastnik wrote: > > > > > More on that, the whole purpose of proposed interface is to debug and > > > not intended to be used by any user space code. > > > > The purpose is to provide raw access to the Surface Serial Hub protocol, > > just like we provide raw access to USB devices and have hidraw devices. > > > > So this goes a litle beyond just debugging; and eventually the choice > > may be made to implement some functionality with userspace drivers, > > just like we do for some HID and USB devices. > > > > Still I agree with you that adding new userspace API is something which > > needs to be considered carefully. So I will look at this closely when > > reviewing this set. > > To add to that: this was previously a debugfs interface but was moved to misc > after review on the initial RFC: > https://lkml.org/lkml/2020/9/24/96
There is a huge difference between the suggestion and final implementation. Greg suggested to add new debug module to the drivers/misc that will open char device explicitly after user loaded that module to debug this hub. However, the author added full blown char device as a first citizen that has all not-break-user constrains. Thanks
