为什么我们需要一个usbkbd的司机当有usbhid？

Question

我发现默认情况下是usbhid控制我的USB键盘。我是通过做rmmod usbhid来发现的。当我移除usbhid时，usb键盘停止工作。注意，usbkbd尚未插入。然后我插入usbkbd，然后键盘又开始工作了。如果键盘可以由通用驱动程序usbhid处理，那么为什么我们需要一个单独的usbkbd？

Answer 1

内核文档中有一个答案：

3.1.2 usbmouse
~~~~~~~~~~~~~~
For embedded systems, for mice with broken HID descriptors and just any
other use when the big usbhid wouldn't be a good choice, there is the
usbmouse driver. It handles USB mice only. It uses a simpler HIDBP
protocol. This also means the mice must support this simpler protocol. Not
all do. If you don't have any strong reason to use this module, use usbhid
instead.

3.1.3 usbkbd
~~~~~~~~~~~~
Much like usbmouse, this module talks to keyboards with a simplified
HIDBP protocol. It's smaller, but doesn't support any extra special keys.
Use usbhid instead if there isn't any special reason to use this.

来自Documentation/input/input.txt