Re: [PATCH net-next 11/12] net: pse-pd: Add support for event reporting using devm_regulator_irq_helper

On Thu, 3 Oct 2024 14:56:21 +0200
Andrew Lunn [off-list ref] wrote:

quoted

quoted

https://docs.kernel.org/power/regulator/consumer.html#regulator-events

Suggests these are internal events, using a notification chain. How
does user space get to know about such events?  

When events appears, _notifier_call_chain() is called which can generate
netlink messages alongside the internal events:
https://elixir.bootlin.com/linux/v6.11.1/source/drivers/regulator/core.c#L4898
 

Ah, O.K.

But is this in the correct 'address space' for the want of a better
term. Everything else to do with PSE is in the networking domain of
netlink. ethtool is used to configure PSE. Shouldn't the notification
also close by to ethtool? When an interface changes state, there is a
notification sent. Maybe we want to piggyback on that?

Indeed, but regulator API already provide such events, which will even be sent
when we enable or disable the PSE. Should we write a second event management.
Using regulator event API allows to report over current internal events to the
parents regulator the power supply of the PSE which could also do something to
avoid smoke.

Or maybe we should add another wrapper which will send PSE ethtool netlink
notification alongside the regulator notifications supported by this patch.

Also, how do regulator events work in combination with network
namespaces? If you move the interface into a different network
namespace, do the regulator events get delivered to the root namespace
or the namespace the interface is in?

regulator events are sent in root namespace.

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com