Bug#243575: X configuration should allow to let out monitor frequencies and allow DDC to get them.
On Fri, Nov 12, 2004 at 11:18:45AM -0800, Daniel Stone wrote:
> On Fri, Nov 12, 2004 at 06:39:00PM +0100, Sven Luther wrote:
> > > I suggest you take a wander through radeon_driver.c one day -- it is
> > > absolutely *not* a couple of registers, and you cannot do it simply.
> >
> > Well, as far as the 3dlabs graphic cards are concerned, it is not only two
> > register, but exactly two bits out of those registers. Or 4 maybe, one for
> > sending, one for receiving, and a timing register for each one if i remember
> > well. Now the radeon_driver.c code is probably full of stuff to first look at
> > the VBE code, then at the apple OF one, and then only fall back to reading per
> > DDC, and finally some fallback for the known case of apple laptop panels which
> > don't have DDC support. Still, the act of actually speaking to the ddc bus is
> > probably using only a few registers and looking at the actual code in
> > radeon_driver.c code at line 812, i see that seems to be indeed the case. In
> > fact there are some stuff to initialize the card, but basically, what happens
> > is that you set following i2c bus registers :
> >
> > [...]
>
> Yeah, understood. I believe you first have to program the CRTCs,
> however, which is a total black art ...
Not in the case i know. Preinit you need to do, and access to comand
registers, but not the actual monitor setup.
> > No, but we should let the user make the choice, at least in medium priority.
> > Hell, a standard debian/sarge install don't even asks about screen resolution
> > and defaults to 800x600. Speak of user friendliness.
>
> I didn't know this; when did that happen?
Since debian-installer sets debconf priority to high by default.
> > > ... which is why any future scheme absolutely must, preferably via ESP.
> >
> > Sorry, i don't know ESP, what is it ?
>
> Extra Sensory Perception -- basically, knowing things that other people
> think.
Hehe, ok, i almost guessed such, but said it must be some strange new bus or
whatnot. Actually even ESP will not work, since the user probably doesn't know
the info you need, so you would rather need real divinatory stuff. :)
> > I can forward to you all those reports stating "why are my icons so big" if
> > you want :). I have load of them.
>
> Er, unless something's changed since I last wandered this code, this
> will only happen if 640x480 is specified in the config file, which it
> shouldn't be. There was no 'oh well, let's try 640' code in X, last I
> saw.
Well, default debconf stuff is 800x600 and 640x480.
> > > I know. This is why I'm suggesting that no automatic tool should ever
> > > be writing out HorizSync or VertRefresh. If it's so bad that it cannot
> > > be automatically probed, then the user can edit the config file. By the
> >
> > No. Then the user can enter the right value in the debconf question.
>
> Your choice.
>
> > > time you're digging for your non-existent monitor manual, it's no better
> > > than a Debconf question.
> >
> > All i am really asking for the time being, is to be able to enter empty values
> > at that debconf question, and leave these fields out of the config file. This
> > i cannot do right now.
>
> (Nor can I.)
>
> > Also note that i right now need to edit the config file in 4 locations to make
> > it work :
> >
> > 1) removing the HorizSync and VertRefresh lines.
>
> ... yes.
>
> > 2) change the driver from ati to radeon since X doesn't know about the
> > second head of my radeon 9200 SE.
>
> Yes, the ati driver apparently needs patching for these cases still; it
> is crack and I personally prefer atimisc/r128/radeon directly, but there
> you go.
Well, there is no choice to use radeon directly, so ...
> > 3) add more reasonable reasonable resolutions than just 800x600 and 640x480.
>
> Yes.
>
> > 4) set my keyboard values. This is better since localization-config came
> > about, since the normal debconf still continued equating powerpc with
> > macintosh, which is obviously false. Still as i am using a french locale and
> > a us keyboard, this is still not working.
>
> Well, you can't win 'em all. :)
Indeed.
> > It is a shame though that we have to resort to localization-config for doing a
> > sensible thing with keyboards though, and not have X debconf's configuration
> > do something more sensible, like i proposed many month ago.
>
> Our experience is that it has been immensely difficult, however -- like
> people who live in Sweden, speak Finnish, and have a US keyboard, or
> something. Covering all the possibilities is really, really, really,
> really, really, really, insanely hard, and honestly about twenty times
> harder than I even really considered.
Well, the thing is that debian-installer gets it right for the console keymap,
but it apparently doesn't mapp one-to-one to X keymaps.
And BTW, the french pmac X keymap is utterly broken.
> > Ok, this will be the major challenge for etch, this and some upstream
> > development to make this aspects easy. I know that David Dawes and other were
> > working on some configuration-less X server, but since they sabotaged
> > themselves that code is lost to us.
>
> Not entirely, actually. One of the more interesting things about the
> X -configure stuff is that it shells out to a policy engine IIRC, which
> means that the policy engine could just call back into Debconf or
> anything; I was thinking about this tonight.
>
> If this is possible, I'll be experimenting with it and seeing if I can't
> get rid of my hand-hacked DDC code which is a mixture of read-edid and
> ddcprobe (plus the egrep/sed mixture for inferring panel resolutions via
> X -probeonly).
Sounds interesting.
> > > (For what it's worth, mum also has an analogue modem.)
> >
> > Yep. I also do support for pegasos users which have them, still you cannot
> > deny that those are being phased out fast, with already words of 15Mb/s ADSL
> > out there.
>
> Not in Bendigo (regional Victoria), there isn't. Well, there's aDSL,
> but last I looked, 256/64 was $au250 a month base, plus some
> *exhorbitant* cost per megabyte. At that price, two-wave satellite is a
> viable equivalent.
Yep, i was just made aware of sattelite solutions myself, but they are still
expensive.
Friendly,
Sven Luther
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