Trying to use Radeon driver on Apple eMac

Stan Cunningham stan.cunningham at
Tue Dec 16 14:01:45 PST 2008


--- On Tue, 12/9/08, Alex Deucher <alexdeucher at> wrote:
> Excellent!  I'll add a MacModel entry for the emac and
> hopefully
> auto-detect code based on the info in /proc/cpuinfo.  One
> last thing
> we need to figure out it the ddc line for the vga
> connector.  If you
> have a chance to test with another monitor try the various
> ConnectorTable option until you are able to get an edid
> from the
> external monitor.  You will only need to adjust 'j'
> in the
> connectortable option. Once that's done you should be
> able to use
> dualhead, etc.
> Do you know if all emacs use these modes or if they are
> specific to
> certain ones?  It they are common, I can have the driver
> add these
> modes automatically.

The EDID for the built-in monitor of all PowerPC Macs can be found under /proc/device-tree. Since it's hard for anyone but Apple to know about every single type of monitor they've put into their computers, wouldn't it be better for the radeon driver to find the EDID at runtime by looking in the OpenFirmware device tree rather than relying on a possibly inaccurate and out of date static quirk list? 

I think the xresprobe utility has a file called ddcprobe/of.c that does exactly that (ie. parses the OpenFirmware device tree and extracts the EDID). Why doesn't the radeon driver just use ddcprobe/of.c? This would seem the most robust way of getting EDID on all Apple PPC computers (iMac, Emac, Clamshell, Powerbook, PowerMac, etc).

Hopefully this will help remove the uncertainty expressed in the following commits:



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