Hi Rodolfo,
On Thu, 5 Feb 2009 14:36:09 +0100, Rodolfo Giometti wrote:
> 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 <giometti@xxxxxxxx>
> ---
> 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;
>
Patch applied, thank you. I've add missing includes of <linux/rwsem.h>
in all 3 files.
--
Jean Delvare
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