On Fri, Aug 18, 2017 at 02:15:31PM +0200, Alexander Steffen wrote:
> In order to avoid delaying the code longer than necessary while still
> giving the TPM enough time to execute the self tests asynchronously, start
> with a small delay between two polls and increase it each round.
>
> Signed-off-by: Alexander Steffen <alexander.stef...@infineon.com>
> ---
> drivers/char/tpm/tpm2-cmd.c | 17 +++++++++--------
> 1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index 7e328d6..e3d4cc3 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -877,20 +877,17 @@ static int tpm2_start_selftest(struct tpm_chip *chip,
> bool full)
> static int tpm2_do_selftest(struct tpm_chip *chip)
> {
> int rc;
> - unsigned int loops;
> - unsigned int delay_msec = 100;
> - unsigned long duration;
> - int i;
> -
> - duration = tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST);
> + unsigned int delay_msec = 20;
> + long duration;
>
> - loops = jiffies_to_msecs(duration) / delay_msec;
> + duration = jiffies_to_msecs(
> + tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST));
>
> rc = tpm2_start_selftest(chip, false);
> if (rc)
> return rc;
>
> - for (i = 0; i < loops; i++) {
> + while (duration > 0) {
> /* Attempt to read a PCR value */
> rc = tpm2_pcr_read(chip, 0, NULL);
> if (rc < 0)
> @@ -900,6 +897,10 @@ static int tpm2_do_selftest(struct tpm_chip *chip)
> break;
>
> msleep(delay_msec);
> + duration -= delay_msec;
> +
> + /* wait longer the next round */
> + delay_msec *= 2;
> }
>
> return rc;
> --
> 2.7.4
>
Reviewed-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
/Jarkko
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