Re: [PATCH v3] of/overlay: add of overlay notifications

[Rob Herring]

On Thu, Mar 3, 2016 at 9:10 AM, Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> wrote:
> This patch add of overlay notifications.
>
> When DT overlays are being added, some drivers/subsystems
> need to see device tree overlays before the changes go into
> the live tree.
>
> This is distinct from reconfig notifiers that are
> post-apply or post-remove and which issue very granular
> notifications without providing access to the context
> of a whole overlay.
>
> The following 4 notificatons are issued:
>   OF_OVERLAY_PRE_APPLY
>   OF_OVERLAY_POST_APPLY
>   OF_OVERLAY_PRE_REMOVE
>   OF_OVERLAY_POST_REMOVE
>
> In the case of pre-apply notification, if the notifier
> returns error, the overlay will be rejected.
>
> This patch exports two functions for registering/unregistering
> notifications:
>   of_overlay_notifier_register(struct notifier_block *nb)
>   of_overlay_notifier_unregister(struct notifier_block *nb)
>
> The of_mutex is held during these notifications. The
> notification data includes pointers to the overlay target
> and the overlay:
>
> struct of_overlay_notify_data {
>        struct device_node *overlay;
>        struct device_node *target;
> };
>
> Signed-off-by: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
> ---
> v2: add missing 'static inline' in of.h
> v3: fix build for !OF_OVERLAY in of.h
>     add a note in the header that the of_mutex is held
> ---
>  drivers/of/overlay.c |   47 ++++++++++++++++++++++++++++++++++++++++++++++-
>  include/linux/of.h   |   25 +++++++++++++++++++++++++
>  2 files changed, 71 insertions(+), 1 deletion(-)

This looks fine to me, but apply it when you have a user.

Acked-by: Rob Herring <robh@xxxxxxxxxx>

Rob