From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wolfram Sang , Wolfram Sang Subject: [PATCH 4.3 085/200] i2c: rcar: disable runtime PM correctly in slave mode Date: Sun, 14 Feb 2016 14:21:32 -0800 Message-Id: <20160214222220.405075880@linuxfoundation.org> In-Reply-To: <20160214222217.084543173@linuxfoundation.org> References: <20160214222217.084543173@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wolfram Sang 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 Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- 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; }