Power Antenna / Bug Sensor accessories always lit up when plugged into link port

[Blaziken257]

Description

A few Japanese-exclusive games published by Smilesoft (Telefang, Bugsite, and Dino Device) use optional accessories through the link port which have LEDs that light up in certain situations (like phone calls in Telefang). These devices are functionally identical.

More information can be found here: https://wiki.telefang.net/Power_Antenna

Technical information can be found here (as well as an emulator that supports the accessories: https://shonumi.github.io/articles/art19.html)

The expected behavior is that these accessories only light up in certain game situations. However, in this GB/GBC core, the accessories are always lit up, even when playing a game that doesn't any link functions. This is probably a minor issue, but it suggests that the core seems to ping the link port even when it is unnecessary.

The issue is not present when using the cartridge slot (or using spiritualized1997's core).

Images

Below are some images. Together, these images show behavior when using the cartridge slot, vs the budude2 GB/GBC core. The images are shrunk down on this page, but they can be clicked on to see larger versions.

In the two images below, Telefang is being played off the cartridge slot -- the first is a Japanese retail cart, and the second is the English patch played on an Everdrive X7. Both the original Power Antenna and Bug Sensor are used interchangeably, but more importantly, they light up during a phone call.

In the two images below, Super Mario Land, a game that doesn't use any link features, is shown. In the first image, a cartridge is used, and the Power Antenna is not lit up (note the lack of the red light).
However, in the second image, the budude2 GB core is used, and the accessory is lit up! This is not the intended behavior, and should not be lit up. (Not shown here, this also happens with the Bug Sensor. Presumably, this also happens with the Telefang 2 Power Antenna, but I do not have one that I can use.)

Also, not shown here, the same issue happens in the GBC core as well.

[budude2]

Yea, I should probably add an option for turning off the cart port/link port. It would save some battery too.