Re: [PATCH 1/1] HID: logitech: add Bolt receiver support for Logitech HID++ devices

[Kateřina Medvědová]

Hello Erik,
I tested your patch on my hardware and found two issues:

1. Both keyboard and mouse inputs stop working correctly. The mouse 
becomes very sensitive and creates events that shouldn't happen 
(sometimes scrolls on its own) and the keyboard's keys are scrambled. I 
verified on my hardware that if you pass the first two of Bolt's 
interfaces (0 boot keyboard and 1 boot mouse) to the generic HID driver 
and only handle interface 2 in the DJ driver, you can keep the extra 
functionality (like battery reporting) without affecting inputs. The 
existing bInterfaceNumber >= no_dj_interfaces check never triggers for 
Bolt. no_dj_interfaces = 3, but the receiver's highest interface number 
is 2, so interfaces 0 and 1 fall through to the DJ path. Here's what 
fixed it:


if (id->driver_data == recvr_type_bolt && intf &&
    intf->altsetting->desc.bInterfaceNumber !=
				LOGITECH_DJ_INTERFACE_NUMBER) {
	hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
	return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
}


2. Bolt devices stay behind after unpairing in userspace (using Solaar). 
The existing driver code doesn't handle Bolt's unpair events so devices 
stay visible after unpairing. Here's how I handled it:

if (djrcv_dev->type == recvr_type_bolt &&
    hidpp_report->report_id == REPORT_ID_HIDPP_SHORT &&
    hidpp_report->sub_id == REPORT_TYPE_NOTIF_DEVICE_UNPAIRED) {
	struct dj_workitem workitem = {
		.device_index = device_index,
		.type = WORKITEM_TYPE_UNPAIRED,
	};

	kfifo_in(&djrcv_dev->notif_fifo, &workitem, sizeof(workitem));
	schedule_work(&djrcv_dev->work);
	spin_unlock_irqrestore(&djrcv_dev->lock, flags);
	return false;
}

Hardware tested:
- Logi Bolt receiver (046d:c548)
- Logi POP Icon Keys
- Logi Lift Vertical
- Logi K650

Happy to do more testing.

Regards,
Kateřina Medvědová