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Groups > linux.kernel > #1304639

[PATCH v3 7/8] i2c: muxes always lock the parent adapter

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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 34a7748b4652..4683777f81ca 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -963,12 +963,7 @@ 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);
 }
 
 /**
@@ -977,12 +972,7 @@ 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);
 }
 
 /**
@@ -991,12 +981,7 @@ 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 9bdebbdcbc61..fcfe51b023c0 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;
@@ -183,6 +207,9 @@ int i2c_add_mux_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

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Thread

[PATCH v3 0/8] i2c mux cleanup and locking update Peter Rosin <peda@lysator.liu.se> - 2016-01-08 16:10 +0100
  [PATCH v3 8/8] i2c-mux: relax locking of the top i2c adapter during i2c controlled muxing Peter Rosin <peda@lysator.liu.se> - 2016-01-08 16:10 +0100
  [PATCH v3 6/8] i2c: allow adapter drivers to override the adapter locking Peter Rosin <peda@lysator.liu.se> - 2016-01-08 16:10 +0100
  [PATCH v3 5/8] i2c-mux: pinctrl: get rid of the driver private struct device pointer Peter Rosin <peda@lysator.liu.se> - 2016-01-08 16:10 +0100
  [PATCH v3 3/8] i2c-mux: move the slave side adapter management to i2c_mux_core Peter Rosin <peda@lysator.liu.se> - 2016-01-08 16:10 +0100
  [PATCH v3 4/8] i2c-mux: remove the mux dev pointer from the mux per channel data Peter Rosin <peda@lysator.liu.se> - 2016-01-08 16:10 +0100
  [PATCH v3 1/8] i2c-mux: add common core data for every mux instance Peter Rosin <peda@lysator.liu.se> - 2016-01-08 16:10 +0100
  [PATCH v3 7/8] i2c: muxes always lock the parent adapter Peter Rosin <peda@lysator.liu.se> - 2016-01-08 16:10 +0100
  [PATCH v3 2/8] i2c-mux: move select and deselect ops to i2c_mux_core Peter Rosin <peda@lysator.liu.se> - 2016-01-08 16:10 +0100

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