Patch "i2c: rcar: disable runtime PM correctly in slave mode" has been added to the 4.3-stable tree

Patch "i2c: rcar: disable runtime PM correctly in slave mode" has been added to the 4.3-stable tree

[gregkh]

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

    i2c: rcar: disable runtime PM correctly in slave mode

to the 4.3-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:
     i2c-rcar-disable-runtime-pm-correctly-in-slave-mode.patch
and it can be found in the queue-4.3 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 b4cd08aa1f53c831e67dc5c6bc9f9acff27abcba Mon Sep 17 00:00:00 2001
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: Wed, 16 Dec 2015 20:05:18 +0100
Subject: i2c: rcar: disable runtime PM correctly in slave mode

From: Wolfram Sang <wsa+renesas@sang-engineering.com>

commit b4cd08aa1f53c831e67dc5c6bc9f9acff27abcba upstream.

When we also are I2C slave, we need to disable runtime PM because the
address detection mechanism needs to be active all the time. However, we
can reenable runtime PM once the slave instance was unregistered. So,
use pm_runtime_get_sync/put to achieve this, since it has proper
refcounting. pm_runtime_allow/forbid is like a global knob controllable
from userspace which is unsuitable here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/i2c/busses/i2c-rcar.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -575,7 +575,7 @@ static int rcar_reg_slave(struct i2c_cli
 	if (slave->flags & I2C_CLIENT_TEN)
 		return -EAFNOSUPPORT;
 
-	pm_runtime_forbid(rcar_i2c_priv_to_dev(priv));
+	pm_runtime_get_sync(rcar_i2c_priv_to_dev(priv));
 
 	priv->slave = slave;
 	rcar_i2c_write(priv, ICSAR, slave->addr);
@@ -597,7 +597,7 @@ static int rcar_unreg_slave(struct i2c_c
 
 	priv->slave = NULL;
 
-	pm_runtime_allow(rcar_i2c_priv_to_dev(priv));
+	pm_runtime_put(rcar_i2c_priv_to_dev(priv));
 
 	return 0;
 }


Patches currently in stable-queue which might be from wsa+renesas@sang-engineering.com are

queue-4.3/i2c-rcar-disable-runtime-pm-correctly-in-slave-mode.patch