* Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> [200916 12:34]: > On Mon, Sep 14, 2020 at 11:09:16AM +0300, Tony Lindgren wrote: > > * 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 :) > > Is it possible to test configuration when you have kernel console enabled but > no getty is run on it (perhaps something with ssh enabled access)? > > Then kernel console should call ->shutdown on detaching, right? I gave this a quick try and Johan is right, shutdown is not called on console uart still even if detached and no getty running on that uart. I could not figure out easily where exactly this gets blocked.. So far I did try setting port->console = 0 on detach, then init it again on attach. Regards, Tony
