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

[Erik Håkansson]

Hi!

On Thursday, 24 September 2026 23:57:05 Central European Summer Time Oleksandr 
Natalenko wrote:

> No idea TBH. The mouse is this one:
> 
> https://www.logitech.com/en-us/shop/p/mx-master-4
> 
> I haven't seen proximity mentioned anywhere is specs. But I can try to sniff
> for these events, just let me know how.

Great, thanks, we can do some tshark capture then. That's what I did locally. 

1. First, in Solaar, make sure diversion is off.

2. Then, find what bus and device your mouse is on:

lsusb -d 046d:c548

It should give an answer like this:
Bus 005 Device 007: ID 046d:c548 Logitech, Inc. Logi Bolt Receiver

3. And from there you get bus=5 and device=7, so do a tshark capture:
sudo tshark -i usbmon5 -Y 'usb.device_address == 7 && usb.urb_type == 0x43 && 
usb.transfer_type == 0x01 && usb.data_len > 0' -x

This should output ALL incoming data, i.e. including every little mouse 
movement, so it will be noisy.
So try to keep the mouse stationary to minimize noise and try to only touch 
the thumbwheel. Both hovering your finger very close but not quite touching, 
then a single tap, and finally just holding your finger still on the wheel.

I saw some information online though that the MX Master 4 supports touch, but 
not tap or proximity, so presumably we'll only get one of the three.

4. Please also give me the output of:
sudo lsusb -v -d 046d:c548 | grep -E 'bInterfaceNumber|bEndpointAddress'
It should list the interfaces on the Bolt receiver, which should be the two 
native HID interfaces and the HID++ interface that I think is for devices with 
touchpads.

5. If you want, you can try the same when the Solaar Divert is set to on as 
well, that would give confirmation that the mouse follows the protocol found 
online.

If you get a lot of data that you don't want to send on the LKML you can just 
send it directly to me if you want :) 

Cheers!
Erik