Re: [PATCH 03/28] nvmem: add a notifier chain

From: Andrew Lunn
Date: Wed Aug 08 2018 - 12:15:42 EST


On Wed, Aug 08, 2018 at 05:31:25PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
>
> Add a blocking notifier chain with two events (add and remove) so that
> users can get notified about the addition of nvmem devices they're
> waiting for.
>
> We'll use this instead of the at24 setup callback in the mityomapl138
> board file.

Hi Bartosz

What context is this notifier chain called in?

I did something similar using the i2c notifier to try to work around
the impending disappearing of the setup callback. But i got lockdep
splats, because the notifier was called while some locks were being
held, so it was not possible to register other i2c devices.

The at24 setup callback is done as part of probe, so no important
locks are held. Are any locks held when this notifier chain is called?

Thanks
Andrew