system – logcat: E QC-QMI : qmi_client [378]: unable to connect to server, errno=[13:Permission denied]

On my Fairphone-2 with Android 9 I had a look into logcat because it is generally unstable since the upgrade to 9 and sometimes gets hot and drains battery like hell. Today I saw this:

378   395 E QC-QMI  : qmi_client (378): unable to connect to server, errno=(13:Permission denied), attempt=60
395   395 W thermal-engine: type=1400 audit(0.0:1056): avc: denied { dac_override } for capability=1 scontext=u:r:thermal-engine:s0 tcontext=u:r:thermal-engine:s0 tclass=capability permissive=0    378   395 E QC-QMI  : qmi_client (378): unable to connect to server after 60 tries... giving up
378   395 E QC-QMI  : qmi_qmux_if_pwr_up_init_ex:  Initialization failed, rc = -1
378   395 E QMI_FW  : QMUXD: WARNING qmi_qmux_if_pwr_up_init failed! rc=-1

The first type of message comes in every second for 1 minute, then the fail is reported, then it starts over.

Any hints appreciated about:

  1. what is qmi_client, possibly WIFI?
  2. which permission could that be, some device or a network endpoint?
  3. which server could that be or is this just any server requested by some app?
  4. can this be somehow related to that thermal-engine, the message of which consistently comes along each time and 378 is actually the PID of the thermal-engine. What is it and why would it want to connect anywhere?