Improving the suspend quirks guessworking

[Matthew Garrett]

On Tue, Mar 25, 2008 at 09:06:09PM +0100, Danny Kukawka wrote:
> On Dienstag, 25. März 2008, Matthew Garrett wrote:
> > The most likely worst case is that using a set of default fallbacks will
> > cause a machine that didn't resume to continue not resuming. The best
> > case is that it helps a machine that wouldn't otherwise resume. 
> 
> But the defaults you use are like get something from /dev/random. It make no 
> sense to set a global default. As I already pointed out several times, there 
> are several vendors where the most machines need other quirks. I don't see 
> why we should use these quirks.

And? The number of machines I've found that *need* a smaller set of 
quirks (rather than a smaller set being sufficient) is small, and 
they're primarily Intel ones - where we don't want to run any quirks 
ever, anyway.

> > The case 
> > you're talking about (hardware resumes graphics in the BIOS, running the
> > quirks breaks it) is so vanishingly unlikely that it's not worth
> > bothering about. Having the BIOS unconditionally rePOST the graphics
> > slows down the resume cycle and causes extra screen flickering under
> > Windows, which worsens the user experience. As a result, almost no
> > hardware does this. So, the probability of breakage is painfully small.
> 
> But in this case you break machines which currently correctly suspend because 
> they don't need any quirks. 

There are approximately no machines which need no quirks, unless you're 
using bleeding-edge i915 DRM or a binary driver.

> > Ugh. Looking at some of the "none" entries in the current hal-info makes
> > me strongly suspect that the only thing restoring video is X or the
> > nvidia binary blob. Oh, ugh.
> 
> I wouldn't be that sure.

Why not? I've *got* some of that hardware, and the only way it'd work 
with the listed quirks is if X is doing the state restoration.

> > <!-- another ASUS Mainboard, this need no quirk -->
> 
> IIRC these are e.g. from s2ram where the suspend normaly work from X and 
> console, so X isn't causing this.

Having quirks listed against a motherboard without integrated graphics 
makes no sense. At all. Ever. You can't claim that a motherboard needs 
no quirks, because you have no idea what graphics card is in it. 

-- 
Matthew Garrett | mjg59 at srcf.ucam.org