tpm: crb: check the error bit only after taking locality

[olivier]

Summary

tpmcrb_transmit() read CRB_CTRL_STS before requesting locality 0. An AMD Pluton fTPM (FrameWork Desktop) using the plain CRB start method reads the control area as all-ones until locality is assigned, so bit 0 looks like a stuck tpmSts and every command failed with EIO.

With RANDOM_ENABLE_TPM the harvester retries every 10 seconds, so this printed "Device has Error bit set" forever.

Test Plan

Before:
"tpmcrb0: Device has Error bit set" every 10s, TPM unusable.

After: no messages in 20 minutes (3-4s expected before), and

tpm2_selftest --fulltest      -> rc=0
tpm2_getcap properties-fixed  -> TPM 2.0, rev 1.59
tpm2_pcrread sha256:0-7       -> all PCRs read
tpm2_getrandom --hex 32       -> distinct values per call

[kbowling]

Seems to match spec as well, CRB control registers are allowed to return 00h or FFh if locality is not owned (https://trustedcomputinggroup.org/wp-content/uploads/PC-Client-Specific-Platform-TPM-Profile-for-TPM-2p0-v1p07_Pub.pdf Table 51)

[kbowling]

Please set MFC to 2 weeks when you commit as I intend to pull the GENERIC change back to stable/15 in about a month barring major issues