approval_X11R6.8.x requested: [Bug 1490] DDC code confused by EDID V1.3 : [Attachment 1122] Fix

Thomas Winischhofer thomas at winischhofer.net
Mon Dec 13 15:40:48 PST 2004


Egbert Eich wrote:
> I took the advice given on page 15 of the 
> 'VESA Enahnced Extended Display Identivication Data 
> - Implementation Guide' published by VESA. As far as 
> I know it is freely available thry the VESA web site. 
> I won't distribute it here.
> This states that these bits are undefined.
> Since this guide lists some 'best practices' we may 
> risk getting wrong data from some displays if we go 
> EDID v1.2.
> 
> Egbert.

Egbert,

using bits 6-0 is not my point (and I completely agree with your 
interpretation). My point is why r->input_dfp is set to DFP only of the 
revision is greater than 2.

I (still) can't find anything on this on page 15 of the document you 
mentioned.

Thomas

> 
> Thomas Winischhofer writes:
>  > Thomas Winischhofer wrote:
>  > > bugzilla-request-daemon at freedesktop.org wrote:
>  > > 
>  > >> Alan Coopersmith <alan.coopersmith at sun.com> has asked  for 
>  > >> approval_X11R6.8.x:
>  > >> Bug 1490: DDC code confused by EDID V1.3
>  > >> https://bugs.freedesktop.org/show_bug.cgi?id=1490
>  > >>
>  > >> Attachment 1122: Fix
>  > >> https://bugs.freedesktop.org/attachment.cgi?id=1122&action=edit
>  > >> _______________________________________________
>  > >> release-wranglers mailing list
>  > >> release-wranglers at lists.freedesktop.org
>  > >> http://lists.freedesktop.org/mailman/listinfo/release-wranglers
>  > >>
>  > > 
>  > > -------
>  > > 
>  > > -get_display_section(Uchar *c, struct disp_features *r)
>  > > +get_display_section(Uchar *c, struct disp_features *r,
>  > > +            struct edid_version *v)
>  > >  {
>  > >      r->input_type = INPUT_TYPE;
>  > > -    r->input_voltage = INPUT_VOLTAGE;
>  > > -    r->input_setup = SETUP;
>  > > -    r->input_sync = SYNC;
>  > > +    if (!DIGITAL(r->input_type)) {
>  > > +    r->input_voltage = INPUT_VOLTAGE;
>  > > +    r->input_setup = SETUP;
>  > > +    r->input_sync = SYNC;
>  > > +    } else if (v->version > 1 || v->revision > 2)
>  > > +    r->input_dfp = DFP;
>  > >      r->hsize = HSIZE_MAX;
>  > >      r->vsize = VSIZE_MAX;
>  > >      r->gamma = GAMMA;
>  > > @@ -97,15 +115,20 @@
>  > >  }
>  > > 
>  > > ------
>  > > 
>  > > Hm, where is it stated that the "digital input" bit requires EDID 
>  > > version >= 1.3?
>  > 
>  > 
>  > OK, the PDF standard (Feb 1999) says that DFP compliant panels are at 
>  > least to support EDID 1.2 (page 10).
>  > 
>  > So the (revision > 2) should be (revision >= 2) in the if statement.
>  > 
>  > Thomas
>  > 
>  > -- 
>  > Thomas Winischhofer
>  > Vienna/Austria
>  > thomas AT winischhofer DOT net	       *** http://www.winischhofer.net
>  > twini AT xfree86 DOT org
>  > _______________________________________________
>  > release-wranglers mailing list
>  > release-wranglers at lists.freedesktop.org
>  > http://lists.freedesktop.org/mailman/listinfo/release-wranglers
> _______________________________________________
> release-wranglers mailing list
> release-wranglers at lists.freedesktop.org
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> 


-- 
Thomas Winischhofer
Vienna/Austria
thomas AT winischhofer DOT net          http://www.winischhofer.net/
twini AT xfree86 DOT org


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