[PATCH v4 17/18] i2c: muxes always lock the parent adapter

From: Peter Rosin <peda@lysator.liu.se>
To: linux-kernel@vger.kernel.org
Cc: Peter Rosin <peda@axentia.se>, Wolfram Sang <wsa@the-dreams.de>,
	Peter Korsgaard <peter.korsgaard@barco.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Jonathan Cameron <jic23@kernel.org>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Peter Meerwald <pmeerw@pmeerw.net>,
	Antti Palosaari <crope@iki.fi>,
	Mauro Carvalho Chehab <mchehab@osg.samsung.com>,
	Rob Herring <robh+dt@kernel.org>,
	Frank Rowand <frowand.list@gmail.com>,
	Grant Likely <grant.likely@linaro.org>,
	Adriana Reus <adriana.reus@intel.com>,
	Viorel Suman <viorel.suman@intel.com>,
	Krzysztof Kozlowski <k.kozlowski@samsung.com>,
	Terry Heo <terryheo@google.com>,
	Hans Verkuil <hans.verkuil@cisco.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Tommi Rantala <tt.rantala@gmail.com>,
	linux-i2c@vger.kernel.org, linux-iio@vger.kernel.org,
	linux-media@vger.kernel.org, devicetree@vger.kernel.org,
	Peter Rosin <peda@lysator.liu.se>
Subject: [PATCH v4 17/18] i2c: muxes always lock the parent adapter
Date: Thu,  3 Mar 2016 23:27:29 +0100	[thread overview]
Message-ID: <1457044050-15230-18-git-send-email-peda@lysator.liu.se> (raw)
In-Reply-To: <1457044050-15230-1-git-send-email-peda@lysator.liu.se>

From: Peter Rosin <peda@axentia.se>

Instead of checking for i2c parent adapters for every lock/unlock, simply
override the locking for muxes to always lock/unlock the parent adapter
directly.

Signed-off-by: Peter Rosin <peda@axentia.se>
---
 drivers/i2c/i2c-core.c | 21 +++------------------
 drivers/i2c/i2c-mux.c  | 27 +++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 946afd8e9f78..6be266c3d39b 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -964,12 +964,7 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
  */
 static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, int flags)
 {
-	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
-
-	if (parent)
-		i2c_lock_adapter(parent);
-	else
-		rt_mutex_lock(&adapter->bus_lock);
+	rt_mutex_lock(&adapter->bus_lock);
 }
 
 /**
@@ -978,12 +973,7 @@ static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, int flags)
  */
 static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, int flags)
 {
-	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
-
-	if (parent)
-		return parent->trylock_bus(parent, flags);
-	else
-		return rt_mutex_trylock(&adapter->bus_lock);
+	return rt_mutex_trylock(&adapter->bus_lock);
 }
 
 /**
@@ -992,12 +982,7 @@ static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, int flags)
  */
 static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, int flags)
 {
-	struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
-
-	if (parent)
-		i2c_unlock_adapter(parent);
-	else
-		rt_mutex_unlock(&adapter->bus_lock);
+	rt_mutex_unlock(&adapter->bus_lock);
 }
 
 static void i2c_dev_set_name(struct i2c_adapter *adap,
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index e7ac7a4a7a83..6f5c70c527b8 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -98,6 +98,30 @@ static unsigned int i2c_mux_parent_classes(struct i2c_adapter *parent)
 	return class;
 }
 
+static void i2c_parent_lock_bus(struct i2c_adapter *adapter, int flags)
+{
+	struct i2c_mux_priv *priv = adapter->algo_data;
+	struct i2c_adapter *parent = priv->muxc->parent;
+
+	parent->lock_bus(parent, flags);
+}
+
+static int i2c_parent_trylock_bus(struct i2c_adapter *adapter, int flags)
+{
+	struct i2c_mux_priv *priv = adapter->algo_data;
+	struct i2c_adapter *parent = priv->muxc->parent;
+
+	return parent->trylock_bus(parent, flags);
+}
+
+static void i2c_parent_unlock_bus(struct i2c_adapter *adapter, int flags)
+{
+	struct i2c_mux_priv *priv = adapter->algo_data;
+	struct i2c_adapter *parent = priv->muxc->parent;
+
+	parent->unlock_bus(parent, flags);
+}
+
 int i2c_mux_reserve_adapters(struct i2c_mux_core *muxc, int adapters)
 {
 	struct i2c_adapter **adapter;
@@ -192,6 +216,9 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
 	priv->adap.retries = parent->retries;
 	priv->adap.timeout = parent->timeout;
 	priv->adap.quirks = parent->quirks;
+	priv->adap.lock_bus = i2c_parent_lock_bus;
+	priv->adap.trylock_bus = i2c_parent_trylock_bus;
+	priv->adap.unlock_bus = i2c_parent_unlock_bus;
 
 	/* Sanity check on class */
 	if (i2c_mux_parent_classes(parent) & class)
-- 
2.1.4
