Re: [PATCH] HID: logitech-hidpp: sync wheel multiplier on wheel mode changes

[Jiri Kosina]

On Mon, 18 May 2026, Lauri Saurus wrote:

> The hid-logitech-hidpp driver enables high resolution scrolling on
> device connect for capable HID++ 2.0 devices. Driver also reads the
> wheel capability and caches the returned high resolution wheel scroll
> multiplier, that is used for scroll scaling when handling wheel scroll
> events.
> 
> Wheel mode can also be set externally through HID++ requests, which
> can leave the cached multiplier stale and cause incorrect scroll
> scaling. If external SetWheelMode HID++ request sets the mode to
> low resolution, the cached multiplier is not updated accordingly. This
> causes extremely slow scrolling since driver expects multiple wheel
> scroll events per detent but is only getting one.
> 
> The fix listens for HID++ SetWheelMode request responses and updates
> the wheel scroll multiplier based on the set high resolution scroll
> mode. The fix has been tested with Logitech G502X lightspeed mouse.
> 
> Signed-off-by: Lauri Saurus <saurla@xxxxxxxxxx>

Applied, thank you.

-- 
Jiri Kosina
SUSE Labs