By using rwsem we can easily manage recursive calls of i2c_scan_static_board_info() function without breaking the locking.
Signed-off-by: Rodolfo Giometti <[email protected]> --- drivers/i2c/i2c-boardinfo.c | 6 +++--- drivers/i2c/i2c-core.c | 4 ++-- drivers/i2c/i2c-core.h | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/i2c-boardinfo.c b/drivers/i2c/i2c-boardinfo.c index ffb35f0..981cdd8 100644 --- a/drivers/i2c/i2c-boardinfo.c +++ b/drivers/i2c/i2c-boardinfo.c @@ -25,7 +25,7 @@ /* These symbols are exported ONLY FOR the i2c core. * No other users will be supported. */ -DEFINE_MUTEX(__i2c_board_lock); +DECLARE_RWSEM(__i2c_board_lock); EXPORT_SYMBOL_GPL(__i2c_board_lock); LIST_HEAD(__i2c_board_list); @@ -63,7 +63,7 @@ i2c_register_board_info(int busnum, { int status; - mutex_lock(&__i2c_board_lock); + down_write(&__i2c_board_lock); /* dynamic bus numbers will be assigned after the last static one */ if (busnum >= __i2c_first_dynamic_bus_num) @@ -84,7 +84,7 @@ i2c_register_board_info(int busnum, list_add_tail(&devinfo->list, &__i2c_board_list); } - mutex_unlock(&__i2c_board_lock); + up_write(&__i2c_board_lock); return status; } diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 3454878..74b89a9 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -408,7 +408,7 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter) { struct i2c_devinfo *devinfo; - mutex_lock(&__i2c_board_lock); + down_read(&__i2c_board_lock); list_for_each_entry(devinfo, &__i2c_board_list, list) { if (devinfo->busnum == adapter->nr && !i2c_new_device(adapter, @@ -417,7 +417,7 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter) i2c_adapter_id(adapter), devinfo->board_info.addr); } - mutex_unlock(&__i2c_board_lock); + up_read(&__i2c_board_lock); } static int i2c_do_add_adapter(struct device_driver *d, void *data) diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h index cd5bff8..e6af064 100644 --- a/drivers/i2c/i2c-core.h +++ b/drivers/i2c/i2c-core.h @@ -25,7 +25,7 @@ struct i2c_devinfo { /* board_lock protects board_list and first_dynamic_bus_num. * only i2c core components are allowed to use these symbols. */ -extern struct mutex __i2c_board_lock; +extern struct rw_semaphore __i2c_board_lock; extern struct list_head __i2c_board_list; extern int __i2c_first_dynamic_bus_num; -- 1.5.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
