I noticed that in recent kernel versions the runtime detection of newly added monitors does not work properly.
When I plug in my TV (DVI2HDMI) after booting I cannot enable it. xrandr correctly shows a new screen and I can even enable the output, but the TV screen stays black. Restarting X does not help.
The driver also seems to recognize the port status after plugging it in (/sys/class/drm/card0-DVI-I-2/status) changes from "disconnected" to "connected".
When I plug the HDMI cable in _before_ booting my computer the TV works just fine.
GFX: Radeon HD 3870
Linux: 2.6-git (issue appeared in 2.6.35) with KMS
What was the last kernel version where this worked? Is the issue still present in 2.6.36rc3? Can you attach your dmesg output and xorg log?
Created attachment 38360 [details]
Xorg log file
Created attachment 38361 [details]
dmesg from linux 2.6.36-rc3 with drm.debug
(In reply to comment #1)
> What was the last kernel version where this worked? Is the issue still present
> in 2.6.36rc3?
I remember that this worked just fine in 2.6.34. The problem was introduced in an early RC of 2.6.35 and is still present in 2.6.36-rc3.
Any chance you could bisect it?
(In reply to comment #5)
> Any chance you could bisect it?
I just experiented a bit and it didn't work with 22.214.171.124 neither with 126.96.36.199. This is why I assume that screen hotplugging never worked with KMS on my R600 - I must have confused it with fglrx which I was also using until now.
And I forgot to say something about the logs I did attach yesterday: the logs are from a system which booted without a second screen attached. After the XSession loaded I plugged in the monitor and enabled it with xrandr.
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