Re: Logitech M705 mouse not disappearing when turned off

On Fri, 2021-01-08 at 12:42 +0100, Bastien Nocera wrote:

On Fri, 2021-01-08 at 12:23 +0100, Bastien Nocera wrote:

quoted

Hey,

I have recently bought a Logitech Marathon Mouse/Performance Plus
M705,
and I ended up with 2 power_supply class batteries for it when it
was
turned off already when using kernel 5.9.13.

Using a newer kernel (5.11-rc2), the power_supply class device
doesn't
disappear either:
<snip>
I'll look into the upower problem soon.

Filed as:
https://gitlab.freedesktop.org/upower/upower/-/issues/134

I actually don't think this is a bug. The docs for "online" mention:
"
Indicates if VBUS is present for the supply. When the supply is
online, and the supply allows it, then it's possible to switch
between online states (e.g. Fixed -> Programmable for a PD_PPS
USB supply so voltage and current can be controlled).
"

So this isn't really something we can use to signal that a device is
plugged in or not.

And the docs for "present" say:
"
Reports whether a battery is present or not in the system.
"

Well, that would mean that the device is there, but no battery is
present. eg. an XBox joypad without batteries but plugged in to the
system via USB.

Looks like a bug in the hidpp kernel code. This is what "solaar show"
shows for the device:
"
  3: Marathon Mouse M705 (M-R0073)
     Device path  : /dev/hidraw4
     WPID         : 406D
     Codename     : M705 (M-R0073)
     Kind         : mouse
     Protocol     : HID++ 4.5
     Polling rate : 8 ms (125Hz)
     Serial number: B14D65DA
     The power switch is located on the base.
     Battery: unknown (device is offline).
"

Cheers