Re: [RFC] Reliable video POSTing on resume (was: Re: [ACPI] Samsung P35, S3, black screen (radeon))

[Pavel Machek]

Hi!

> >>Rumors say that notebooks no longer have video bios at C000h:0; rumors
> >>say that video BIOS on notebooks is simply integrated into main system
> >>BIOS. I personaly do not know if rumors are true, but PCs are ugly
> >>machines....
> >>							
> >
> >
> >A small number of laptop systems are known to pull this trick. There are
> >other problems too - the video bios boot may make other assumptions
> >about access to PCI space, configuration, interrupts, timers etc.
> >
> >Some systems (intel notably) appear to expect you to use the bios
> >save/restore video state not re-POST.
> 
> Isn't that what it's there for? In any context other than save/restore I 
> wouldn't think using the BIOS was a good approach. But this is a special 
> case, and if there's a BIOS function which does the right thing, it 
> would seem to be easier to assume that the BIOS works than that the 
> driver can do every operation for a clean restart.
> 
> The problem is that while POST leaves the video in a known state, it may 
> not the known state you want, nor is it a given that you can get from 
> there to where you were on suspend. PC hardware isn't always that 
> dependable.

Eh? POST leaves video in 80x25 text mode, and we know how to handle
that mode just fine... Historically that's what we ran our consoles
at, so X can handle it etc.
								Pavel
-- 
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/