X can't run at full monitor res, but plymouth/rhgb can?

[Chris Smart]

On Wed, Oct 20, 2010 at 9:35 AM, Sam Varshavchik <mrsam at courier-mta.com> wrote:

> After I relocated the monitor, and attached a 35' long VGA cable via the
> DVI-VGA adapter, the X desktop, and only the X desktop, now comes up with an
> ugly maximum resolution of 1024x768. system-config-display gives me that as
> the max available resolution.

Well I'm no expert, but to me it seems like you're getting signal/data
loss over that length of cable. KMS probably detects resolutions
differently to X and might not need lots of EDID information. If you
plug in a shorter cable, I'm guessing it will work fine, even at the
new location. The higher the resolution, the shorter your cable must
be to carry enough signal.

If it is causing the issue, and you need the longer cable, you might
want to think about a booster.

Having said that, you might be able to craft your own xorg.conf which
manually specifies all your modelines, etc, and turns off EDID - to do
this, plug a shorter cable back in, start X and grab the log file with
all the correctly detected settings. Use this info to craft your own
xorg.conf.

Anyway, just a thought or two.

-c