From 611e12ea0f121a31d9e9c4ce2a18a77abc2f28d6 Mon Sep 17 00:00:00 2001
From: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Date: Mon, 27 Jul 2015 17:30:49 +0300
Subject: [PATCH] i2c: core: manage i2c bus device refcount in
i2c_[get|put]_adapter
In addition to module_get()/module_put() add get_device()/put_device()
calls into i2c_get_adapter()/i2c_put_adapter() exported
interfaces. This is done to lock I2C bus device, if it is in use by a
client.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
drivers/i2c/i2c-core.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index c83e4d13cfc5c4..f80992d0a60808 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -2413,9 +2413,15 @@ struct i2c_adapter *i2c_get_adapter(int nr)
mutex_lock(&core_lock);
adapter = idr_find(&i2c_adapter_idr, nr);
- if (adapter && !try_module_get(adapter->owner))
+ if (!adapter)
+ goto exit;
+
+ if (try_module_get(adapter->owner))
+ get_device(&adapter->dev);
+ else
adapter = NULL;
+ exit:
mutex_unlock(&core_lock);
return adapter;
}
@@ -2423,8 +2429,11 @@ EXPORT_SYMBOL(i2c_get_adapter);
void i2c_put_adapter(struct i2c_adapter *adap)
{
- if (adap)
- module_put(adap->owner);
+ if (!adap)
+ return;
+
+ put_device(&adap->dev);
+ module_put(adap->owner);
}
EXPORT_SYMBOL(i2c_put_adapter);
--
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