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

On Sep 23 2026, Oleksandr Natalenko wrote:

Hello.

On úterý 22. září 2026 19:40:26, středoevropský letní čas Erik Håkansson wrote:

quoted

This series aims to fix high-resolution wheel handling for Logitech devices
connected through Bolt receivers as well as respect user settings for
scroll behaviour.

Patch 1 is Rafael Passos’s original implementation:

https://lore.kernel.org/linux-input/20260904034843.1340846-1-rafael@rcpassos.me/ (local)

His patch routes Bolt wheel movement through the HID++ child, where the
device’s HiRes Wheel multiplier can be applied. Patch 2 builds on
Rafael’s work by 1. supporting both high-resolution and low-resolution
scroll events, and 2. preserving user-selected high-resolution and
inversion settings.

The follow-up patch was developed with reference to the patches and
reported behavior in Magnetar-OS’s `logitech-bolt-hidpp-dkms` repository:

https://github.com/Magnetar-OS/logitech-bolt-hidpp-dkms/tree/main/patches

So my assumption right now is that the reason for the divergent results
people have had with the two different fix approaches (i.e. either passing
interface 0 and 1 as DJ interfaces, or Rafael's approach), where it works
for some, and only sometimes, etc. is that with user settings coming from
Solaar, we may end up in weird states.
For example, in the original patch, high-resolution events would go through
the generic HID which would treat each tick as a full wheel event, thus 
scaling the scroll way too far. That was solved with Rafael's patch but
that would instead fail to handle low-resolution events if high resolution
was turned off in Solaar while use_hidpp remained enabled, so a low-resolution
delta would be treated as high-resolution, which would result instead in a 
too slow scroll. Possibly, when Oleksandr switched devices, Solaar reapplied
some saved user settings, which conflicted with the driver logic.

With this patch, user settings from Solaar (or elsewhere) for high-resolution
mode and scroll inversion will be respected, 
and scrolling should work both in high-resolution and low-resolution mode.
However, if user-space turns off the use_hidpp setting while high_resolution
remains on, this will route high-resolution scroll events to generic HID.
Thus, when high_resolution is on for a Bolt device, the driver will
force use_hidpp to be on during initialisation or reinitialisation, because
otherwise the scaling issue will return.
Solaar may still, after driver initialisation, reapply a saved use_hidpp
setting of off while high_resolution remains on, or the user may change it
to off, which will cause the issue even with this patch.

In theory, it should be possible to look at incoming setWheelMode responses
or notifications and, just like on initialisation, enforce use_hidpp as long
as high_resolution is set on a Bolt device. However, I don't know how Solaar
will behave then. There's a risk it will trigger a back-and-forth if Solaar
reapplies its saved setting after the kernel corrects it. Also, even if that
doesn't happen, we should respect user choice even for use_hidpp. Perhaps
the Solaar team can be informed about the problem so they can add a warning
text.

Note that I don't have a Bolt mouse to test this with, and my theory is 
mostly inferred, so I would appreciate very much if people with various
Bolt mice could test it out. Also great if you try different settings in 
Solaar, but note that use_hidpp must be on if high_resolution is on, so 
either set it to on in Solaar, or to ignore.

Link: https://lore.kernel.org/linux-input/20260712003051.338194-2-erikhakan@gmail.com/ (local)
Link: https://lore.kernel.org/linux-input/20260901-bolt-scroll-fix-v1-1-58bca7ae487f@protonmail.com/ (local)
Link: https://lore.kernel.org/linux-input/LYMlyJcyQt29e1KlLnEoLw@natalenko.name/ (local)
Link: https://lore.kernel.org/linux-input/20260920094508.39682-1-roman.stingler@gmail.com/ (local)
Signed-off-by: Erik Håkansson <redacted>
---
Erik Håkansson (1):
      HID: logitech-hidpp: fix Bolt wheel mode handling

Rafael Passos (1):
      HID: logitech-hidpp: fix hi-res scroll for Bolt-connected MX Master

 drivers/hid/hid-logitech-hidpp.c | 147 ++++++++++++++++++++++++++++++++-------
 1 file changed, 123 insertions(+), 24 deletions(-)
---
base-commit: 022eb347ff3a48281e7e69c3addcb11bf24afa53
change-id: 20260921-feature-bolt-fix-5f1f642496df

Best regards,

Not sure if I'm testing this right, but with v7.3-rc4 and these two patches scrolling works OK as long as I keep "Scroll Wheel Resolution" in Solaar off. Unlike with unpatched kernel, scrolling doesn't go crazy if I switch between devices. But if I switch "Scroll Wheel Resolution" on, scrolling jumps crazy again.

Hopefully we've got all of the involved people here.

Honestly, this whole situation has been running for too long: Bolt can't
be handled as a DJ receiver, and all the quirks I'm seeing here are
making things even worse, with the "as long as I keep [some user
settings] off".

Bolt in kernel was adding in 7.3, so I'm going to revert it now, and
we'll have to have a fully working plan for an eventual inclusion in a
future kernel version.

Cheers,
Benjamin