On 09/03/2017 07:49 PM, Sakari Ailus wrote:
> Registering a notifier has required the knowledge of struct v4l2_device
> for the reason that sub-devices generally are registered to the
> v4l2_device (as well as the media device, also available through
> v4l2_device).
>
> This information is not available for sub-device drivers at probe time.
>
> What this patch does is that it allows registering notifiers without
> having v4l2_device around. Instead the sub-device pointer is stored to the
> notifier. Once the sub-device of the driver that registered the notifier
> is registered, the notifier will gain the knowledge of the v4l2_device,
> and the binding of async sub-devices from the sub-device driver's notifier
> may proceed.
>
> The master notifier's complete callback is only called when all sub-device
> notifiers are completed.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-async.c | 153 +++++++++++++++++++++++++++++------
> include/media/v4l2-async.h | 19 ++++-
> 2 files changed, 146 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index 70d02378b48f..55d7886103d2 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -25,6 +25,10 @@
> #include <media/v4l2-fwnode.h>
> #include <media/v4l2-subdev.h>
>
> +static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
> + struct v4l2_subdev *sd,
> + struct v4l2_async_subdev *asd);
> +
> static bool match_i2c(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
> {
> #if IS_ENABLED(CONFIG_I2C)
> @@ -101,14 +105,69 @@ static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *
> return NULL;
> }
>
> +static bool v4l2_async_subdev_notifiers_complete(
> + struct v4l2_async_notifier *notifier)
> +{
> + struct v4l2_async_notifier *n;
> +
> + list_for_each_entry(n, ¬ifier->notifiers, notifiers) {
> + if (!n->master)
> + return false;
> + }
> +
> + return true;
> +}
> +
> +#define notifier_v4l2_dev(n) \
> + (!!(n)->v4l2_dev ? (n)->v4l2_dev : \
> + !!(n)->master ? (n)->master->v4l2_dev : NULL)
> +
> +static struct v4l2_async_notifier *v4l2_async_get_subdev_notifier(
> + struct v4l2_async_notifier *notifier, struct v4l2_subdev *sd)
Why pass the notifier argument when it is not actually used in the function?
Is this function needed at all? As far as I can see the sd always belongs to
the given notifier, otherwise the v4l2_async_belongs() call would fail.
And v4l2_async_belongs() is always called before v4l2_async_test_notify().
This could all do with some more code comments. I'm having a difficult time
understanding it all.
I'll wait for v8 before continuing this.
Regards,
Hans
> +{
> + struct v4l2_async_notifier *n;
> +
> + list_for_each_entry(n, ¬ifier_list, list) {
> + if (n->sd == sd)
> + return n;
> + }
> +
> + return NULL;
> +}
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
