kms howto - is there one?

Adam Williamson awilliam at redhat.com
Fri Mar 19 19:00:42 UTC 2010


On Fri, 2010-03-19 at 13:32 -0400, Felix Miata wrote:

> > And as I said, that behaviour is equally 'wrong'. The other distros
> > you've tried probably aren't using kernel modesetting, hence the
> > differing behaviour.
> 
> I'm having a problem understanding how something that has long been
> functioning acceptably can be considered wrong. 

It allows you to set modes that the monitor isn't actually capable of.

> I posit that KMS
> configurations simply aren't yet mature enough to deal with absent DDC/EDID.

You posit incorrectly. :) The case of absent monitor information is
explicitly handled by using a generic monitor configuration which is
restricted to a maximum 1024x768 resolution, in order to avoid the
possibility of hardware damage.

(Yes, you say only really old monitors can be damaged, but hey, that
depends on your perspective. To me, *your* monitors are already 'really
old', but obviously you want us to care about those. Why should we care
about a _small inconvenience_ to your ancient monitors, but not
_irreversible damage_ to someone else's slightly-more-ancient ones?)

It occurs to me that drakx11 in Mandriva probably still allows manual
monitor configuration; do you have to do this on Mandriva to make it
work? If so, that would explain why it 'works' in Mandriva, selecting a
monitor (or high-resolution-capable 'generic' monitor definition) in
Mandriva is equivalent to manually sticking a monitor definition in your
xorg.conf in Fedora. I don't know anything about how other distributions
handle it.
-- 
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Fedora Talk: adamwill AT fedoraproject DOT org
http://www.happyassassin.net



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