Re: [PATCH 0/2] HID: logitech-hidpp: fix Bolt hi-res wheel handling

[Erik Håkansson]

Hi!

On Saturday, 26 September 2026 13:39:18 Central European Summer Time Oleksandr 
Natalenko wrote:

> 
> This is touching:
> 
> 0000  00 23 e7 90 c5 8d ff ff 43 01 83 03 01 00 2d 00   .#......C.....-.
> 0010  76 ae b7 6a 00 00 00 00 01 1a 0e 00 00 00 00 00   v..j............
> 0020  14 00 00 00 14 00 00 00 00 00 00 00 00 00 00 00   ................
> 0030  01 00 00 00 00 00 00 00 04 02 00 00 00 00 00 00   ................
> 0040  11 02 13 00 00 00 00 00 00 02 00 00 00 00 00 00   ................
> 0050  00 00 00 00                                       ....
> 
> This is untouching:
> 
> 0000  00 23 e7 90 c5 8d ff ff 43 01 83 03 01 00 2d 00   .#......C.....-.
> 0010  79 ae b7 6a 00 00 00 00 5e c1 05 00 00 00 00 00   y..j....^.......
> 0020  14 00 00 00 14 00 00 00 00 00 00 00 00 00 00 00   ................
> 0030  01 00 00 00 00 00 00 00 04 02 00 00 00 00 00 00   ................
> 0040  11 02 13 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
> 0050  00 00 00 00

Great, thanks! This confirms that touch, but not tap or proximity, comes in on 
HID++ but not at all on native HID.
I don't think evdev has a very good output to map it to though, so maybe I'll 
leave it unmapped for now. BTN_TOUCH combined with some appropriate BTN_TOOL_* 
for denoting thumbwheel would be a semantic fit, but I think there's a risk 
that userspace starts to interpret the device as a touchscreen then, if I 
understand the input event codes documentation correctly:
https://github.com/torvalds/linux/blob/master/Documentation/input/event-codes.rst

By the way, when Thumbwheel Divertion is on, do you get the regular thumbwheel 
scroll events on HID++ too? That would be the 81 (native HID) or 83 (HID++) on 
byte 11 in the hex output :)

Cheers
Erik