Re: [Suspend-devel] 2.6.25-rc2 System no longer powers off aftersuspend-to-disk. Screen becomes green.

Ingo Molnar
2008-02-22T13:06:51Z

* Matthew Garrett <mjg59@srcf.ucam.org> wrote:

> The s2ram command has a built-in whitelist used to set up video
> rePOSTing. If you want to test, reboot and do
>
> echo mem >/sys/power/state
>
> without i915 being loaded. If you get a console back on resume then
> the platform is reinitialising video for you, but otherwise it's your
> userspace.

btw., why isnt there an in-kernel whitelist, with perhaps a dynamic,
convenient /debug/s2r/whitelist append-API for distros (and testers) to
add more entries to the whitelist/blacklist? (for cases where the kernel
whitelist has not caught up yet) Which would eventually converge to
Utopia: s2ram that just works out of box.

This would be a lot more flexible (people could even temporarily extend
the whitelist via rc.local if need to be, etc.), a lot more robust and a
lot more user friendly than the "dont use /sys/power/state, rely on some
user-space tool to work around bugs" approach.

Really, i couldnt make the s2ram API/quirks situation much worse even if
i deliberately tried to design the whole code to be as hard to use and
as confusing as possible :-/ These types of half-kernel half-userspace
solutions usually result in constant finger-pointing and constant lag,
and they result in about the crappiest user experience that is possible
to achieve physically.

( Sorry about the strong words, while there's lots of good and positive
development lately i havent seen much change in this particular area
of s2ram in the past 1-2 years, and the whole chain is only as strong
as the weakest link - so someone finally has to deliver this message
to the cozy fire of s2r hackers while our testers and users are
standing out in the cold rain ... )

Ingo