Bug 100301 - AMD/ATI Radeon HD 4670 doesn't turn on main screen (iMac mid 2010)
Summary: AMD/ATI Radeon HD 4670 doesn't turn on main screen (iMac mid 2010)
Status: NEW
Alias: None
Product: Drivers
Classification: Unclassified
Component: Video(Other) (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: drivers_video-other
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2015-06-22 14:16 UTC by Micael Dias
Modified: 2018-04-06 07:21 UTC (History)
3 users (show)

See Also:
Kernel Version: 4.1.0-rc8
Subsystem:
Regression: No
Bisected commit-id:


Attachments
dmesg after booting the computer and turning the screen on manually (72.89 KB, text/plain)
2015-06-22 14:16 UTC, Micael Dias
Details

Description Micael Dias 2015-06-22 14:16:43 UTC
Created attachment 180551 [details]
dmesg after booting the computer and turning the screen on manually

When booting the kernel the screen of this iMac 21.5" (mid 2010) turns off. I believe this is when entering KMS.

If I access the iMac via ssh I see that:
/sys/class/drm/card0-eDP-1/status -> "connected"
/sys/class/drm/card0-DP-1/status -> "disconnected"

I can get the monitor to turn on if I:
echo "on" > /sys/class/drm/card0-DP-1/status

Everything works perfectly fine after I turn the screen on with that command, including 3D acceleration.

If I boot with "nomodeset" the screen doesn't turn off.

I don't have an external monitor with DisplayPort that I can connect to this iMac to test if that's where the video output is going, but some google search reveals that some users confirm the output is going to the external DisplayPort output by default.
Comment 1 Florian Echtler 2018-04-06 07:21:10 UTC
I think I'm running into the same bug with kernel 4.13 on a 27" iMac from 2009 (model iMac10,1). Turning the monitor on via sysfs doesn't yet seem to work, though, but the sysfs output and other behaviour seem identical.

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