Re: [gentoo-user] KVM problems - anyone know _why_ it happens?

[Mark Knecht <markknecht@gmail.com>]

On Sun, Jan 22, 2012 at 10:58 AM, Michael Mol <mikemol@gmail.com> wrote:
> On Sun, Jan 22, 2012 at 1:07 PM, G.Wolfe Woodbury <redwolfe@gmail.com> wrote:
>> On 01/22/2012 12:42 PM, Mark Knecht wrote:
>>>
>>> I played a bit with get-edid | parse-edid. Logically that stuff even
>>> working says the VGA monitor cable is bidirectional. I started wondering if
>>> the KVM messes up the data coming back, or what else might be going on.
>>> Thanks for the ideas, Mark
>>
>> Many of the cheap KVM models do, indeed, mess up the EDID data coming from
>> the monitor.  I suspect that this is from old design specs that have too
>> much pull-up/pull-down on the EDID lead since the boxen haven been
>> re-engineered for newer, higher resolution and higher speed monitors.
>>
>> I have had problems specifically with the BELKIN KVMs.
>>
>> It may also be that the video drivers for Linux are just enough different
>> (necessarily) from the MSFT drivers to not reliably sense the EDID return
>> signals.
>
> Concur. It sounds like the EDID block isn't making it back or is
> somehow messed up. x11-misc/read-edid would help in investigating that
> kind of issue.
>

Yeah, I did that sort of stuff already. It didn't tell me anything
specific as best I could tell. However I haven't done it with the KVM
out. Maybe comparing the two responses would give some clues.

Also, thanks for the pointer to xvidtune. Interesting little app.
QUESTION: Do you know how to get the data for each monitor/video card
combo? So far I haven't figured out how to tell it Screen2. Seems to
only give me Screen0 as best I can tell.

I'm a bit nervous to just start trying things.

Cheers,
Mark