XHC WHB04B development?

I was just in the garage using the mill with the pendant. And thought that maybe I should post a mood picture, so we don't forget why we put effort on improving the pendant software
 

Still trying to learn exactly where in the code it fails.
It doesn't reconnect, that's for sure. If it had, it wouldn't have been an issue.
I overwrite the log and, alas, no saved useful log.
"Unfortunately" I didn't get a crash today when I worked with the machine.
I like the whb04b a lot.It's worth spending some time improving stability.

 

Okay. Once you get a crash, post the output here and we can try to work it through together. Please ensure that you have some print statement in place of the commented out assert call, so if it fails there, we know about it. Something like:

Got a crash today. Seems to be the usual way. At mode and screen switch.I have seen that libusb debug printout several times before.Attach are the log and also usb.cc and xhc-whb04b6.cc to be able to follow my printouts. 

That was unexpected. For all the world, it looks like this get stuck in libusb somewhere. After the "is Open" debug text, the code does the following:
1. Function call XhcWhb04b6Component::enableReceiveAsyncTransfer()
2. From XhcWhb04b6Component::enableReceiveAsyncTransfer() call Usb::setupAsyncTransfer()
3. From Usb::setupAsyncTransfer() call libusb_submit_transfer()
4. From libusb_submit_transfer() call libusb_unref_device()
5. In libusb_unref_device() print "libusb: debug [libusb_unref_device] destroy device"
6. libusb_submit_transfer() never returns is my guess
Maybe some deadlock inside libusb. Whether that would be from some bug in libusb or because of some improper handling in the xhc-whb04b-6 component, I cannot say. At least at the moment. I'll look into it some more, but not right now.

I made some changes in my firmware so I could generate a disconnect at will. Ten times in a row, I got libusb_submit_transfer to return non-zero in Usb::setupAsyncTransfer. And every time, the pendant reconnected to the xhc-whb04b-6 component without issue. In other words, I am unable to reproduce your issue, which more or less means I cannot help you directly. However, you mentioned that you had to change libusb_init_context() to libusb_init(). It appears libusb_init_context() was introduced in libusb 1.0.27:
libusb.sourceforge.io/api-1.0/group__lib...e12023b7399003c50470
Looking at my system, I have libusb 1.0.28-1. I think it would be well worth trying to upgrade libusb. Or if you don't want to do that, you could use LinuxCNC 2.9.8 as a "live cd" to see if that fixes the issue. This would actually be better, since it's possible that the issue could be in the Linux kernel itself.