At 2023-07-25 22:08:44, "Oliver Neukum" <oneukum@xxxxxxxx> wrote: >On 25.07.23 15:54, Dingyan Li wrote: > >> If we can't "deprecate" ioctls, can we change the returned contents of existing ones? > >No. Absolutely not. That is totally unacceptable. It would be much >worse than just removing the support. > > Regards > Oliver Got it, I guess this is for backward-compatibility. I also have another thought. USBDEVFS_CONNINFO_EX is kind of special and used to retrieve contents of variable length. If you check proc_conninfo_ex(), I think maybe we can append a new member to "struct usbdevfs_conninfo_ex" without breaking backward-compatibility. By this way, we can avoid adding a new ioctl. Or even more aggressively, drop USBDEVFS_GET_SPEED and force everyone to use USBDEVFS_CONNINFO_EX since it can also return device speed. Regards, Dingyan
