Currently, there is an unnecessary 1 msec delay added in i2c_nuvoton_write_status() for the successful case. This function is called multiple times during send() and recv(), which implies adding multiple extra delays for every TPM operation. This patch calls usleep_range() only if retry is to be done. Cc: stable@xxxxxxxxxxxxxxx ( linux-4.8) Signed-off-by: Nayna Jain <nayna@xxxxxxxxxxxxxxxxxx> Reviewed-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> --- drivers/char/tpm/tpm_i2c_nuvoton.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c index 0c98c42..c642877 100644 --- a/drivers/char/tpm/tpm_i2c_nuvoton.c +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c @@ -124,8 +124,9 @@ static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data) /* this causes the current command to be aborted */ for (i = 0, status = -1; i < TPM_I2C_RETRY_COUNT && status < 0; i++) { status = i2c_nuvoton_write_buf(client, TPM_STS, 1, &data); - usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY - + TPM_I2C_DELAY_RANGE); + if (status < 0) + usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY + + TPM_I2C_DELAY_RANGE); } return status; } -- 2.9.3