USB HID device only detected after replugging

[Qbicz]

Describe the bug
Device uses USB HID class. It used to register to host and send HID data over USB without issues.
However, with Zephyr revision 19de7ec (Nordic NCS 812f5d5) device is not recognized after boot. You need to unplug and replug it to make USB HID work.

Sequence of USB callbacks that I receive:

- Device boot (cable connected from start)

USB_DC_CONNECTED,
USB_DC_SUSPEND,
USB_DC_RESUME,
USB_DC_RESET,
USB_DC_RESET,
USB_DC_RESET,
USB_DC_RESET,
USB_DC_CONFIGURED.

- Device is started, but not recognized by host.
- Unplug

USB_DC_SUSPEND,
USB_DC_DISCONNECTED,

- Replug
USB_DC_CONNECTED,
USB_DC_SUSPEND,
USB_DC_RESUME,
USB_DC_RESET,
USB_DC_RESET,
USB_DC_RESET,
USB_DC_RESET,
USB_DC_CONFIGURED.

- Now the device is found by USB host and reports can be sent.

Impact
Showstopper. Device should be operational right after boot.

[Qbicz]

FYI @pawelzadrozniak @masz-nordic

[Qbicz]

I checked and the problem was introduced between cf85618 (good, February 22) and d9876be (bad, merged on March 5). I cannot bisect further because I would have to make project compile for every revision in between (which would take quite some time).

In other words, it first occured on NCS upmerge 5eea43c.

[Qbicz]

Bug was in application - it was not handling multiple RESET / RESUME callbacks. Fixed in nrfconnect/sdk-nrf#566