On Mon, Sep 04, 2017 at 02:17:21AM +0200, Rafael J. Wysocki wrote:

OTOH I'm starting to think that direct_complete is only theoretically
useful and may not be actually set very often in practice, whereas it
adds significant complexity to the code, so I'm not sure about it any
more.

That makes me come out of the woodwork as a direct_complete fan:

Runtime resuming a discrete GPU on a modern dual GPU laptop takes about
1.5 sec, runtime resuming Thunderbolt controllers more than 2 sec.
A discrete GPU easily consumes 10W, a Thunderbolt controller 2W.

So not having direct_complete would noticeably delay system suspend and
resume as well as reduce battery life.

Lukas