From 611e12ea0f121a31d9e9c4ce2a18a77abc2f28d6 Mon Sep 17 00:00:00 2001 From: Vladimir Zapolskiy 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 Signed-off-by: Wolfram Sang --- 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 c83e4d13cfc5..f80992d0a608 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);