Hello, building ibmvtpm I noticed gcc warning complaining that second word of struct ibmvtpm_crq in tpm_ibmvtpm_suspend is uninitialized.
The structure is defined as struct ibmvtpm_crq { u8 valid; u8 msg; __be16 len; __be32 data; __be64 reserved; } __attribute__((packed, aligned(8))); initialized as struct ibmvtpm_crq crq; u64 *buf = (u64 *) &crq; ... crq.valid = (u8)IBMVTPM_VALID_CMD; crq.msg = (u8)VTPM_PREPARE_TO_SUSPEND; and submitted with rc = ibmvtpm_send_crq(ibmvtpm->vdev, cpu_to_be64(buf[0]), cpu_to_be64(buf[1])); which means that the second word indeed contains purely garbage. This is repeated a few times in the driver so I added memset to quiet gcc and make behavior deterministic in case the unused fields get some meaning in the future. However, in tpm_ibmvtpm_send the structure is initialized as struct ibmvtpm_crq crq; __be64 *word = (__be64 *)&crq; ... crq.valid = (u8)IBMVTPM_VALID_CMD; crq.msg = (u8)VTPM_TPM_COMMAND; crq.len = cpu_to_be16(count); crq.data = cpu_to_be32(ibmvtpm->rtce_dma_handle); and submitted with rc = ibmvtpm_send_crq(ibmvtpm->vdev, be64_to_cpu(word[0]), be64_to_cpu(word[1])); meaning it is swapped twice. Where is the interface defined? Are the command arguments passed as BE subfields (the second case was correct before adding the extra whole word swap) or BE words (the first case doing whole word swap is correct)? Thanks Michal