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 Mesa: git libdrm: git xf86-video-ati: git
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 2.6.34.6 neither with 2.6.33.7. 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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