Comment 203 for bug 370173

One thing that I forgot, my WLAN would be 03:00.0 Network controller: Broadcom Corporation BCM4328 802.11a/b/g/n (rev 03)

@Prabhakar Nagral:

Simply using the power manager from a different release is anything but simple.
It's not as if "the power manager" is one thing, power management is a cooperation of:

-) hardware
-) firmware (BIOS/ACPI, whatever)
-) kernel
-) userspace

Worse, some of these parts are almost certainly "defective" (in a tight sense), e.g. I wouldn't count on 99% of the BIOSes implementing full specs, beyond what a certain legacy OS from the north west needs. So even changes how the kernel interacts with the BIOS that have no direct relevance (at first glance) to power management, can influence the situation. Furthermore, it all can depend upon:

-) configuration (hardware/software)
-) production variance/tolerance. (E.g. some devices X of manufacturer Y work, some don't.)

The problems that this issue has, are IMHO:

-) it's still not really reproducible.
-) it's still probably a mix of different causes (e.g. there are enough cases that are not hibernation related)
-) it seems to be not reproducible even on the same hardware, there seems to be people running officially the same hardware that have/have not problems.
-) it's dependent upon the environment. E.g. while some hard cases have the problem always, others only experience them in warm weather.
-) some cases might be hardware related. Enough cases are not so.

So generally speaking, as a software developer, this issue is classification wise pure hell to fix. At least Ubuntu has assigned somebody that takes a look into this. Don't expect a solution that fixes all problems quickly :(

@Andy

Wondering, do we have a git repo of the kernels used by ubuntu, wondering if I might try out git bisect myself on my laptop?

Andreas