Patch "tpm: add sleep only for retry in i2c_nuvoton_write_status()" has been added to the 4.9-stable tree

Patch "tpm: add sleep only for retry in i2c_nuvoton_write_status()" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    tpm: add sleep only for retry in i2c_nuvoton_write_status()

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tpm-add-sleep-only-for-retry-in-i2c_nuvoton_write_status.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 0afb7118ae021e80ecf70f5a3336e0935505518a Mon Sep 17 00:00:00 2001
From: Nayna Jain <nayna@linux.vnet.ibm.com>
Date: Fri, 10 Mar 2017 13:45:54 -0500
Subject: tpm: add sleep only for retry in i2c_nuvoton_write_status()

From: Nayna Jain <nayna@linux.vnet.ibm.com>

commit 0afb7118ae021e80ecf70f5a3336e0935505518a upstream.

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.

Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/char/tpm/tpm_i2c_nuvoton.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- 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(stru
 	/* 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;
 }


Patches currently in stable-queue which might be from nayna@linux.vnet.ibm.com are

queue-4.9/tpm-msleep-delays-replace-with-usleep_range-in-i2c-nuvoton-driver.patch
queue-4.9/tpm-add-sleep-only-for-retry-in-i2c_nuvoton_write_status.patch