The first thing IsPreparedForAttestation currently does is checking if tpm is ready. Only then it checks the attestation database status. That optimization leads to the opposite effects - checking the tpm status leads to a trip to tpm_managerd, which can bock there waiting for a long tpm operation.
1) Avoid, if possible, checking the rtpm readiness status in IsPreparedForAttestation - rely on the database state. [Needs to be confirmed that it will not lead to wrong results in corner cases.]
2) Cache, if possible, the tpm readiness status and request only wen change is possible (see also issue 777679).
 

The first thing IsPreparedForAttestation currently does is checking if tpm is ready. Only then it checks the attestation database status. That optimization leads to the opposite effects - checking the tpm status leads to a trip to tpm_managerd, which can bock there waiting for a long tpm operation.
1) Avoid, if possible, checking the tpm readiness status in IsPreparedForAttestation - rely on the database state. [Needs to be confirmed that it will not lead to wrong results in corner cases.]
2) Cache, if possible, the tpm readiness status and request only when change is possible (see also issue 777679).