Re: [PATCH] HID: usbhid: switch HIDBP devices to boot protocol

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jun 02, 2026 at 09:48:35AM +0800, Xu Rao wrote:
> usbkbd and usbmouse are HID Boot Protocol drivers. They do not
> parse report descriptors before decoding interrupt reports; instead,
> they interpret input data as the fixed boot keyboard and boot mouse
> formats.
> 
> The HID specification defines SET_PROTOCOL as the class request
> to select report or boot protocol. Boot subclass devices may power
> up or return from reset in report protocol, and hosts are expected
> to select the protocol they intend to use.
> 
> Do not depend on firmware or a previous driver to leave the
> interface in boot protocol. Send SET_PROTOCOL(BOOT) during probe
> before the interrupt URB can be opened.
> 
> Keep failures non-fatal. Some devices may reject the request while
> still sending boot-compatible reports. For those devices, the
> existing driver behavior is preferable.

Do you really use these drivers for devices?  If so, why?

And shouldn't the failure be fatal?  If not, why even attempt to send
it?

How was this tested?  On what devices?

thanks,

greg k-h