Re: [PATCH v3 5/5] console: Introduce ->exit() callback

From: Andy Shevchenko
Date: Thu Jan 30 2020 - 05:01:05 EST


On Thu, Jan 30, 2020 at 10:09:17AM +0100, Petr Mladek wrote:
> On Mon 2020-01-27 13:47:19, Andy Shevchenko wrote:
> > Some consoles might require special operations on unregistering. For example,
> > serial console, when registered in the kernel, keeps power on for entire time,
> > until it gets unregistered. For such cases to have a balance we would provide
> > ->exit() callback.
>
> Is there any plan to use this callback, please?
>
> The console init, setup, registration code needs a clean up,
> definitely. If you plan some rework, I would like to understand
> the bigger picture before we start adding new callbacks.

Yes, as mentioned in the commit message I would like to use it for balancing
runtime PM reference counters in the UART code later on.

It will look like:

->setup():
pm_runtime_get(...);

->exit():
pm_runtime_put(...);

The current operations have no needs to be undone.

--
With Best Regards,
Andy Shevchenko