[Openchrome-users] [openChrome] #247: Guess HorizSync and VertRefresh if DDC fails

[OpenChrome Trac]

#247: Guess HorizSync and VertRefresh if DDC fails
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Reporter:  btmorex  |       Owner:  somebody
    Type:  defect   |      Status:  new     
Priority:  major    |   Component:  3d      
 Version:           |    Keywords:          
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 On my laptop (Averatec 3225), DDC completely fails. As far as I can tell,
 it returns no useful information. However, openchrome seems to already
 know which laptop I have:

 (--) CHROME(0): Detected Averatec 322x.

 and guesses the correct panel size:

 (WW) CHROME(0): Unable to retrieve PanelSize: using default (1024x768)

 I think it should further guess some reasonable HorizSync and VertRefresh
 values so that no manual configuration is necessary. I've found that
 setting HorizSync to 28-51 and VertRefresh to 43-60 lets openchrome
 generate a working modeline for 1024x768 at 60hz. I have no idea if those are
 correct, but they at least work. Since these laptops were only sold with
 one panel, I think it would be reasonable to just use these values as
 defaults if they aren't specified (and DDC fails, which I'm assuming
 happens with all Averatec 322X laptops).

 One of the difference I've found with new linux installers is that they
 completely rely upon DDC (where in the past they would assume some
 conservative monitor values in xorg.conf). Since DDC doesn't work, X
 simply won't start with new installers and it's pretty difficult to figure
 out why.

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Ticket URL: <http://www.openchrome.org/trac/ticket/247>
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