[PATCH v3 5/5] tpm: use tpm_msleep() value as max delay

From: Nayna Jain
Date: Wed Oct 04 2017 - 06:30:15 EST


Currently, tpm_msleep() uses delay_msec as the minimum value in
usleep_range. However, that is the maximum time we want to wait.
The function is modified to use the delay_msec as the maximum
value, not the minimum value.

After this change, performance on a TPM 1.2 with an 8 byte
burstcount for 1000 extends improved from ~9sec to ~8sec.

Fixes: 3b9af007869("tpm: replace msleep() with usleep_range() in TPM 1.2/
2.0 generic drivers")

Signed-off-by: Nayna Jain <nayna@xxxxxxxxxxxxxxxxxx>
Acked-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 4fc83ac7abeb..644de70de2cc 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -528,8 +528,8 @@ int tpm_pm_resume(struct device *dev);

static inline void tpm_msleep(unsigned int delay_msec)
{
- usleep_range(delay_msec * 1000,
- (delay_msec * 1000) + TPM_TIMEOUT_RANGE_US);
+ usleep_range((delay_msec * 1000) - TPM_TIMEOUT_RANGE_US,
+ delay_msec * 1000);
};

struct tpm_chip *tpm_chip_find_get(int chip_num);
--
2.13.3