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Subject[PATCH v2 0/4] additional TPM performance improvements
Date
After further discussions with the Device Driver working group (ddwg),
the following changes were made:

* Check for burstcount at least once to confirm the TPM is ready to accept
the data. Similarly, query for the TPM Expect status as sanity check at
the end.

* Make the sleep for status check during send() in the loop less than
5msec.

* Make the sleep in the loop while querying for burstcount less than
5msec.

Below is the list of patches along with the performance improvements
seen with a TPM 1.2 with an 8 byte burstcount for 1000 extends:

Patch |Improvement(time in sec)

tpm: ignore burstcount to improve tpm_tis | ~41 - ~14
send() performance.

tpm: define __wait_for_tpm_stat to specify | ~14 - ~10
variable polling sleep time

tpm: reduce tpm_msleep() time in | ~10 - ~9
get_burstcount()

tpm: modify tpm_msleep() function to have | ~9 - ~8
max range

Changelog v2:

* Add module parameter to handle ignoring of burst count during
tpm tis send() operation.
* Add improvements over sleep time to reduce delays.

Nayna Jain (4):
tpm: ignore burstcount to improve tpm_tis send() performance.
tpm: define __wait_for_tpm_stat to specify variable polling sleep time
tpm: reduce tpm_msleep() time in get_burstcount()
tpm: use tpm_msleep() value as max delay

Documentation/admin-guide/kernel-parameters.txt | 8 ++++++
drivers/char/tpm/tpm-interface.c | 15 ++++++++--
drivers/char/tpm/tpm.h | 7 +++--
drivers/char/tpm/tpm_tis_core.c | 37 +++++++++++++++++++------
4 files changed, 53 insertions(+), 14 deletions(-)

--
2.13.3

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