Bluetooth passthrough error/crash

GreenT · (This post was last modified: 03-31-2019, 09:13 AM by GreenT.)

Recently got Bluetooth passthrough going with an IOGear GBU421 adapter.

When I can get Skyward Sword to launch successfully, it works very well. The problem is that half of the time or more Dolphin freezes/crashes just after putting the following error up on screen:

A "IPCEvent" event was scheduled from the wrong thread (non-CPU).

Ignore and continue?

There are three buttons in the dialog box: Yes, Ignore for this session, and No. None of them are clickable. Dolphin is frozen, and I have to kill it with the Task Manager.

Sometimes this doesn't happen. Skyward Sword starts normally, and everything works well at least until I quit playing and exit. Then, the next time I try to run Skyward Sword, it either fails as described previously, or it works. There doesn't seem to be any rhyme or reason to the failures/successes. I might be able to run the game three times in a row with no crashes. Or it might fail three times in a row.

I have spent a couple days searching, trying different troubleshooting steps, updating/deleting/installing drivers, updating/deleting/reverting/reinstalling Dolphin. I am currently running the pr-7216 version of Dolphin, outside of the main branch, which was supposed to fix the issue. While it does seem like the crash happens less often, it still happens at least 50% of the time. (Prior to switching to this version, the crashes were more like 80 or 90% of the time.)

Is there any progress on troubleshooting this issue? It looks like people first started reporting it last summer, and I haven't seen anything in my searches that shows new information about it.

GreenT · 04-02-2019, 12:00 PM #2

Bump. Nothing new on this issue?

**JMC47** · 04-02-2019, 12:11 PM #3

Nothing we can tell you. I'll link it to the dev that did bluetooth passthrough but beyond that it's mostly out of our control as we're relying on hardware.

GreenT · 04-02-2019, 12:31 PM #4

Thanks, JMC47. It kind of takes the shine off the apple, if you get my meaning. Bluetooth passthrough really is better for certain games, like Skyward Sword. But it might take several attempts to get it to run without crashing when Bluetooth passthrough is enabled.

Do you know if the crashes only happen with certain Bluetooth adapters? Or does it happen with all of them?

**Helios** · (This post was last modified: 04-02-2019, 12:38 PM by Helios.)

It's random. The only 100% reliable adapter is a wii BT module soldered to a voltage regulator and a USB cable.

There are some slight issues with vsync at that point but those are too obscure for anybody with the capability to solve them to reproduce.

GreenT · 04-02-2019, 12:55 PM #6

Wait, what specifically is random? From what I can gather through searching the forum, the complaints people had about modules other than the Wii originals were all about performance, syncing multiple Wii remotes, remembering synced remotes, input lag, etc. Not crashes. Or rather, I saw nothing about crashes before the Dolphin 5.0-8098 release.

trihy · (This post was last modified: 04-02-2019, 01:38 PM by trihy.)

Remember to test different bt passthrough drivers.

You can install with zadig, and try libusbk, winusb, libusb. Everyone has slight differences on Dolphin performance. I got Dolphin wii menú crashes everywhere with libusbk and were mostly solved by using winusb. Another example, with libusb I cannot sync more than one controller.

If that doesnt help, consider building a wii bt module dongle. Is not hard if you have basic soldering skill or could ask to a friend.

There is a thread with all the info and pictures.

GreenT · 04-02-2019, 01:03 PM #8

trihy -- I've been through all the various driver options. Currently using WinUSB, but previously tried the other options.

To be clear, I can run Wii games with my current config, but it might take several attempts to launch a game to get it to launch without crashing. If it DOES launch without crashing, it's rock-solid for as long as I care to play, or as long as I don't stop the emulation. If I stop the emulation/kill the game, it may not start again next time, or the time after that, or after that, etc.

trihy · (This post was last modified: 04-02-2019, 01:48 PM by trihy.)

Dont you have another bt dongle?

Just to make sure if dongle Brand/model is causing crashes.

I have a super generic and cheap one that Works great for one wiimote.

Have you tried this workaround?

Quote:Hi, I found this thread after following the pull request that linked it. I'm also having the same issue, however I have found a reliable workaround that will (hopefully) help debug the issue. I get the error every time I start up a game, however if I go into the Controller settings and toggle between "Passthrough a Bluetooth Adapter" and "Emulate the Wii's Bluetooth Adapter", then go back to Bluetooth Passthrough and hit Close, the error will not happen on next game boot.

**Helios** · 04-02-2019, 01:42 PM **#10**

Also worth pointing out that this passthrough stuff was largely developed on Linux where bullying USB to do what we want is much, much easier. Windows was a "support at best effort" deal because Windows really doesn't like giving exclusive, low level control of USB devices to userspace apps.

Unfortunately, suggesting you change your entire OS to make Dolphin's passthrough work well is insane, but if you want this fixed right now, that's your option. Beyond that, it's mostly hoping that the person who wrote the feature to show up again and see if there's anything further we can do on Windows to force it to work. And there may not be.