edid from an external monitor cant be received. BUT after a suspend/resume cycle the radeonhd driver is caple of retrieving the edid information from the same monitor!
After a cold start the edid information is missing.
Created attachment 12880 [details]
log from cold start
Created attachment 12881 [details]
x log after suspend/resume cycle and restart of X server
stopping the x server from a cold start after disabling the PANEL ouput, like:
$ xrandr -q
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 1440 x 1440
1440x900 60.0 +
DVI-I_1/digital connected 1024x768+0+0 0mm x 0mm
The external connected monitor is switch off correctly and the vga console is correctly displayed only on the PANEL.
Doing the same after a suspend/resume cycle the external connected monitor stays on. so you actually see the vga console on PANEL and DVI-I_1/digital.
Known issue with macbooks. On our TODO list.
I will reassign this to me as the I2C subsystem is my task - unfortunately I cannot promise that I can do too much about it unless I get access to such a device.
I recognized that I can quite reliably get ddc to work on my display at home after I do a suspend to ram cycle. However here at work this *never* helped (different display) ... so It might be a timing thing...
This one shoukld be fixed now.
I did test this on a MacBook that I had for half an hour. There I got DDC after applying 2b16734b998e657a426af5b9dc332700cba2c9be.
Closing it for now. Please reopen if you still see problems.
See last comment.
It seems to work for analogous output so far. However it does not for DVI, actually DVI does not seem to work at all with current git...
Could this be a connector problem? I assume that you run analog over the same DVI-I connector using a dongle. DDC uses the same lines for analog or digital.
From our conversation on IRC I it looks like these problems are unrelated. Still please catch me on IRC so that we can look into what you are seeing some more.
Closing this for now.
OK, I can confirm that it is fixed. The problem I reported on IRC was a user error (or oddity of the Dell 2407W if you want - DVI-D needs to be selected on the DELL otherwise randr will report disconnected)