Re: [PATCH 2/2] serial: core: fix console port-lock regression

From: Tony Lindgren
Date: Mon Sep 14 2020 - 04:11:54 EST


* Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> [200910 09:27]:
> +Cc: Tony, let me add Tony to the discussion.
>
> On Thu, Sep 10, 2020 at 09:35:27AM +0200, Johan Hovold wrote:
> > And what about power management
> > which was the reason for wanting this on OMAP in the first place; tty
> > core never calls shutdown() for a console port, not even when it's been
> > detached using the new interface.
>
> That is interesting... Tony, do we have OMAP case working because of luck?

8250_omap won't do anything unless autosuspend_timeout is configured for
the uart(s). If configured, then the 8250_omap will idle when console is
detached and the PM runtime usage count held by console is decremented, and
the configured autosuspend_timeout expires.

The console is still kept open by getty, so I don't see why shutdown() would
be called for the console port. But maybe I don't follow what you're
concerned about, let me know if you want me to check something :)

Regards,

Tony