Comment 13 for bug 1421455

Yeah it seems likely that some driver is probably being slow in its late_resume handler. There may be something in dmesg which shows how long individual late_resume calls are making, I can't remember (there may also be some debug option which has to be enabled).

Iirc the reason we have to wait for the fb state to change was because you can hit deadlocks with some of the phone kernels if you write state changes to /sys/power/state without waiting. Android also waits for the framebuffer state to change, so that's the only arrangement that's probably tested by the phone makers as well.