When connecting a beamer via VGA, this external monitor is not recognized. This seems to be a regression of the i915 kernel driver. I am using archlinux, if that matters. Using kernel 4.6.5 everything works as expected, but since kernel 4.7 things are broken. Also kernel version 4.8 does not work. The hardware is a lenovo laptop T450s model, which has a VGA connector and display port. Display resolution of the laptop panel is 1920x1080. - Kernel 4.6.5, connecting via VGA to a beamer: Works and gives 1024x768 resolution. - Kernel 4.7 or 4.8, connecting via VGA to a beamer: Does not work. - Kernel 4.7 or 4.8, connecting via a VGA-to-display-port adapter to the beamer: Does not work. - Kernel 4.7 or 4.8, connecting via a HDMI-to-display-port adapter to the beamer: Works and gives 1920x1080 resolution. For the cases where the beamer is not recognized, the output of xrandr is as follows: Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767 eDP1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 310mm x 170mm 1920x1080 60.05*+ 1400x1050 59.98 1600x900 60.00 1280x1024 60.02 1280x960 60.00 1368x768 60.00 1280x720 60.00 1024x768 60.00 1024x576 60.00 960x540 60.00 800x600 60.32 56.25 864x486 60.00 640x480 59.94 720x405 60.00 640x360 60.00 DP1 disconnected (normal left inverted right x axis y axis) DP2 disconnected (normal left inverted right x axis y axis) HDMI1 disconnected (normal left inverted right x axis y axis) HDMI2 disconnected (normal left inverted right x axis y axis) VIRTUAL1 disconnected (normal left inverted right x axis y axis) Interestingly, connecting to an ordinary monitor via the VGA port works and gives a resolution of 1680x1050.
Created attachment 127085 [details] dmesg for kernel 4.6.5 with drm.debug=14 desmg with a working kernel version 4.6.5.
Created attachment 127086 [details] systemd journal for kernel 4.6.5 with drm.debug=14 I booted the laptop with the VGA connector already plugged in. After booting i remove the VGA cable and plugged it in again.
Created attachment 127087 [details] dmesg for kernel 4.8 with drm.debug=14 dmesg with a broken kernel version 4.8.
Created attachment 127088 [details] systemd journal for kernel 4.8 with drm.debug=14 I booted the laptop with the VGA connector already plugged in. After booting i remove the VGA cable and plugged it in again.
Probably a duplicate of bug 83348. The fix is in now, so please test git://anongit.freedesktop.org/drm-intel drm-intel-nightly
Can i cherry-pick those two commits on top of kernel v4.8 release? Or are there any other commits in git://anongit.freedesktop.org/drm-intel drm-intel-nightly that those two commits depend on?
(In reply to philipp.reinkemeier from comment #6) > Can i cherry-pick those two commits on top of kernel v4.8 release? Or are > there any other commits in git://anongit.freedesktop.org/drm-intel > drm-intel-nightly that those two commits depend on? You can try :) Haven't really checked whether there were any significant changes in those areas since 4.8. Perhaps not.
*** This bug has been marked as a duplicate of bug 83348 ***
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