Re: OMAP serial runtime PM and autosuspend (was: Re: [PATCH 4/7] dt-bindings: gnss: add u-blox binding))

[Tony Lindgren]

* Johan Hovold <johan@xxxxxxxxxx> [180509 13:12]:
> While this seems to fix the idling of closed ports here too, I'm not
> sure we can move use_autosuspend to startup() like this.
> 
> First, this flag should be set before registering the tty so that udev
> can be used to update the attributes.
> 
> Second, this prevents setting the autosuspend delay through sysfs when
> the port is closed (when autosuspend is disabled).

Yeah I noticed that too yesterday.

> It seems we really should not be using the negative autosuspend to
> configure the RPM behaviour the way these drivers do. Perhaps a new
> mechanism is needed.

Hmm well simply defaulting to "on" instead of "auto" and setting the
autosuspend_ms to 3000 by default might be doable. I think that way
we can keep use_autosuspend() in probe. Let's hope there are no
existing use cases that would break with that.

> But I'm afraid I don't have time to look at this today.

Sure np thanks,

Tony