Re: Battery indication for Logitech devices

[Bastien Nocera <hadess@hadess.net>]

On Mon, 2022-04-04 at 12:12 +0200, Bastien Nocera wrote:
> On Mon, 2022-04-04 at 09:10 +0200, Nestor Lopez Casado wrote:
> > Hello,
> > 
> > I've got this from asking internally:
> > 
> > " The information should be accurate in both BAS and HIDPP
> > interfaces.
> > However, today the BAS interface is limited. Version  2.0 will be
> > better but not yet released. As you have access to the HIDPP, I
> > recommend using only this one. Like this, the type of connection
> > can
> > be ignored (BLE or USB dongle) "
> 
> As per the patch I just sent (HID: logitech-hidpp: Add Signature
> M650),
> it will unfortunately be difficult to disable the battery reporting
> directly from bluetoothd.
> 
> We can detect whether a Bluetooth device supports HID++, as it has a
> GATT attribute with a Logitech specific UUID[1] (more info/specs
> welcome), but not all the HID++ capable Bluetooth devices seem to be
> detected by the kernel and they need to be added to a list.
> 
> Ideally, the kernel could enable HID++ support for all the Bluetooth
> HID++-capable devices, and we could easily block reporting in upower
> or
> bluetoothd without having to care at runtime about whether there's a
> separate battery reporting interface because we could assume it was
> always there.
> 
> Any ideas on how to do that?

Asking this again.

Is there a full list somewhere of all the Bluetooth devices that
support HID++ or a way to detect them so we can avoid the piecemeal
approach currently taken:
https://lore.kernel.org/linux-input/20220404100311.3304-1-hadess@hadess.net/

Once we know for certain what all those Logitech devices are, we can
start blocking them in upower or bluez.

Cheers