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>
Reviewed-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.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 8e940a5..2178437 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;
tpm_msleep(delay_msec);
+ duration -= delay_msec;
+
+ /* wait longer the next round */
+ delay_msec *= 2;
}
return rc;
--
2.7.4
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
tpmdd-devel mailing list
tpmdd-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/tpmdd-devel
