The existing TPM polling code sleeps in each loop iteration for time in msecs ranging from 1 msecs to 5 msecs. However, many of the TPM commands complete much faster, resulting in unnecessary delays. This set of patches identifies such iterations and optimizes the sleep time. The first patch replaces TPM_POLL_SLEEP with TPM_TIMEOUT_POLL and moves it from tpm_tis_core.c to tpm.h as an enum with value 1 msecs. The second patch further reduces the TPM poll sleep time in get_burstcount() and wait_for_tpm_stat() in tpm_tis_core.c by calling usleep_range() directly. The change is only in the polling time, and the maximum timeout is still maintained the same. Thus, it should not affect the overall existing behavior. Changelog: v3: tpm: reduce poll sleep time in tpm_transmit() * added testing platform information * updated patch description for more clarity on reasoning tpm: reduce polling time to usecs for even finer granularity * added testing platform information * added Jarkko's and Mimi's Reviewed-by v2: tpm: reduce poll sleep time in tpm_transmit() * merged previously defined two patches into this. * updated patch description as per Jarkko's feedback tpm: reduce polling time to usecs for even finer granularity * directly use usleep_range with finer granularity less than 1msec Nayna Jain (2): tpm: reduce poll sleep time in tpm_transmit() tpm: reduce polling time to usecs for even finer granularity drivers/char/tpm/tpm-interface.c | 2 +- drivers/char/tpm/tpm.h | 5 ++++- drivers/char/tpm/tpm_tis_core.c | 11 +++-------- 3 files changed, 8 insertions(+), 10 deletions(-) -- 2.13.3
