pl bossart wrote at Tuesday, May 17, 2011 4:12 PM:
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Perhaps the vendor-specific data space could be useful for matching audio ports to X displays; there is a 64-bit Port_ID in the ELD that might be used for that, or we could define X/Linux/Unix as the vendor, and specify the format of the vendor-specific data in a way that defines this mapping.
Sounds complicated...The spec says this PortID field is "a ""canned"" field that would be populated through implementation specific mean of default programming before the graphic driver is loaded". Duh?
I'm pretty sure our HW doesn't initialize this to anything meaningful before the video driver runs.
The standard "Monitor Name String" may be easier to use...
Do you mean co-opt this field and store alternate data in it? The real monitor name for both monitors in my dual-head setup are the same...
That said, the internal APIs our graphics driver uses to write the ELD is currently limited to 96 bytes (the size of the standardized section of the ELD). I'm not sure yet if that's simply because 96 bytes was all that was needed, or if that also ended up being encoded as a HW design limitation.
Looks like the max for ELDv2 is 80 bytes for the baseline+4 for the header.
Oh yeah; I'd calculated assuming SADs were 4 bytes but they're 3.