From 92980756979a9c51be0275f395f4e89c42cf199a Mon Sep 17 00:00:00 2001
From: Nayna Jain <nayna@linux.vnet.ibm.com>
Date: Mon, 2 Apr 2018 21:50:06 +0530
Subject: [PATCH] tpm: move the delay_msec increment after sleep in
 tpm_transmit()

References: bsc#1082555
Patch-mainline: v4.18-rc1
Git-commit: 92980756979a9c51be0275f395f4e89c42cf199a

Commit e2fb992d82c6 ("tpm: add retry logic") introduced a new loop to
handle the TPM2_RC_RETRY error. The loop retries the command after
sleeping for the specified time, which is incremented exponentially in
every iteration.

Unfortunately, the loop doubles the time before sleeping, causing the
initial sleep to be doubled. This patch fixes the initial sleep time.

Fixes: commit e2fb992d82c6 ("tpm: add retry logic")
Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 drivers/char/tpm/tpm-interface.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index c43a9e28995e..6201aab374e6 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -587,7 +587,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 		 */
 		if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
 			break;
-		delay_msec *= 2;
+
 		if (delay_msec > TPM2_DURATION_LONG) {
 			if (rc == TPM2_RC_RETRY)
 				dev_err(&chip->dev, "in retry loop\n");
@@ -597,6 +597,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 			break;
 		}
 		tpm_msleep(delay_msec);
+		delay_msec *= 2;
 		memcpy(buf, save, save_size);
 	}
 	return ret;
-- 
2.13.7