2018-08-08 18:13 GMT+02:00 Andrew Lunn <andrew@xxxxxxx>: > 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 In the case of at24 it would be called from at24_probe() -> nvmem_register() in process context. Would you mind testing it? Would be great to see if it works on multiple setups. Bart