CMSIS Dap USB Bulk SWO Doesn't Work

[jonathanherbstgrapple]

I have a CMSIS Dap device which supports bulk SWO. When I try to use it with pyOCD I get an exception.

Exception in thread SWVReader:
Traceback (most recent call last):
  File "venv/lib/python3.10/site-packages/pyocd/probe/cmsis_dap_probe.py", line 709, in swo_read
    data = self._link.swo_read()
  File "venv/lib/python3.10/site-packages/pyocd/probe/pydapaccess/dap_access_cmsis_dap.py", line 1041, in swo_read
    return self._interface.read_swo()
  File "venv/lib/python3.10/site-packages/pyocd/probe/pydapaccess/interface/pyusb_v2_backend.py", line 254, in read_swo
    raise DAPAccessIntf.DeviceError(f"Probe {self.serial_number} read thread exited unexpectedly") \
pyocd.probe.pydapaccess.dap_access_api.DAPAccessIntf.DeviceError: Probe 0123456789 read thread exited unexpectedly

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/jonathan/.pyenv/versions/3.10.12/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
  File "venv/lib/python3.10/site-packages/pyocd/trace/swv.py", line 200, in run
    data = self._session.probe.swo_read()
  File "venv/lib/python3.10/site-packages/pyocd/probe/cmsis_dap_probe.py", line 713, in swo_read
    raise self._convert_exception(exc) from exc
pyocd.core.exceptions.ProbeError: Probe 0123456789 read thread exited unexpectedly

I did some poking and I found that there doesn't seem to be an exception in the swo thread, but the _swo_thread_did_exit variable from PyUSBv2 is set to True when the thread is still running. I think this could happen if the PyUSBv2 instance is closed then reused. If I set _swo_thread_did_exit to false in start_swo this seems to fix the problem, but I'm not sure how this class is supposed to be treated. Should this class support closing and reusing?

[TeoMahnic]

Hi @jonathanherbstgrapple, thank you for reporting this.
As mentioned in #1755, this issue should now be resolved. If the problem persists, please feel free to reopen this issue or open a new one.