Hi Mauro,
On Tue, Oct 31, 2017 at 02:22:59PM -0400, Mauro Carvalho Chehab wrote:
> There is a get/put operation in order to get firmware is_available
> data there at the __v4l2_async_notifier_parse_fwnode_endpoints()
> function. However, instead of using it, the code just reads again
> without the lock. That's probably a mistake, as a similar code on
> another function use the cached value.
>
> This solves this smatch warning:
>
> drivers/media/v4l2-core/v4l2-fwnode.c:453:8: warning: variable 'is_available' set but not used [-Wunused-but-set-variable]
> bool is_available;
> ^~~~~~~~~~~~
>
> Fixes: 9ca465312132 ("media: v4l: fwnode: Support generic parsing of graph endpoints in a device")
> Cc: Sakari Ailus <sakari.ailus@xxxxxx>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-fwnode.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
> index 3b9c6afb49a3..681b192420d9 100644
> --- a/drivers/media/v4l2-core/v4l2-fwnode.c
> +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
> @@ -455,8 +455,7 @@ static int __v4l2_async_notifier_parse_fwnode_endpoints(
> dev_fwnode = fwnode_graph_get_port_parent(fwnode);
> is_available = fwnode_device_is_available(dev_fwnode);
> fwnode_handle_put(dev_fwnode);
> -
> - if (!fwnode_device_is_available(dev_fwnode))
> + if (!is_available)
> continue;
>
> if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
This is actually a bug: dev_fwnode isn't guaranteed to be there once
fwnode_handle_put() has been called on it. Good catch!
--
Cheers,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx
