I have three monitors, two 4K and one 1920x1200, all lined up horizontally: [4k][4k][1920x1200]. This configuration worked fine until I upgraded to stretch (testing) a few weeks ago. Now only the two 4k monitors are usable, the third is off (by default) or if I force it on using xrandr it just mirrors.
When I run xrandr it reports a maximum horizontal resolution of $ xrandr | head -1 Screen 0: minimum 320 x 200, current 7680 x 2160, maximum 8192 x 8192 8192. But I need at least $ xrandr | egrep ' connected' | sed 's:^.* \([0-9][0-9]*\)x.*$:\1:' | awk '{t += $1} END {print t}' 9600 9600. (Further hardware details below.) Two question. (a) What happened? Is this due to wayland? Is this a regression? Should I report a bug? (b) Can I fix it? (If so, I'll doc on the appropriate debian wiki.) --Barak A. Pearlmutter <b...@debian.org> http://barak.pearlmutter.net ---------------------------------------------------------------- FURTHER DETAILS ---------------------------------------------------------------- The two 4k displays are daisy-chained on a displayport output, the 1920x1200 is on a VGA connector. $ ps auxww|egrep '/()X' Debian-+ 1724 0.0 0.2 284208 44644 tty1 Sl+ Nov07 0:00 /usr/bin/Xwayland :1024 -rootless -noreset -listen 4 -listen 5 -displayfd 6 barak 1818 0.4 0.8 478732 134336 tty2 S+ Nov07 6:53 /usr/lib/xorg/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -background none -noreset -keeptty -verbose 3 $ dpkg --search xorg/Xorg xserver-xorg-core: /usr/lib/xorg/Xorg $ dpkg --status xserver-xorg-core | egrep Version: Version: 2:1.18.4-2 $ dpkg --status xserver-xorg-video-intel | egrep Version: Version: 2:2.99.917+git20160706-1 $ lspci | egrep VGA 00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller (rev 06) $ xrandr | egrep -A1 -v 'disconnected|^ ' Screen 0: minimum 320 x 200, current 7680 x 2160, maximum 8192 x 8192 VGA-1 connected 1920x1200+0+0 (normal left inverted right x axis y axis) 518mm x 324mm 1920x1200 59.95*+ -- DP-1-8 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 621mm x 341mm 3840x2160 29.98*+ 30.00 29.97 -- DP-1-1-8 connected 3840x2160+3840+0 (normal left inverted right x axis y axis) 621mm x 341mm 3840x2160 29.98*+ 30.00 29.97 $ xdpyinfo name of display: :0 version number: 11.0 vendor string: The X.Org Foundation vendor release number: 11804000 X.Org version: 1.18.4 maximum request size: 16777212 bytes motion buffer size: 256 bitmap unit, bit order, padding: 32, LSBFirst, 32 image byte order: LSBFirst number of supported pixmap formats: 7 supported pixmap formats: depth 1, bits_per_pixel 1, scanline_pad 32 depth 4, bits_per_pixel 8, scanline_pad 32 depth 8, bits_per_pixel 8, scanline_pad 32 depth 15, bits_per_pixel 16, scanline_pad 32 depth 16, bits_per_pixel 16, scanline_pad 32 depth 24, bits_per_pixel 32, scanline_pad 32 depth 32, bits_per_pixel 32, scanline_pad 32 keycode range: minimum 8, maximum 255 focus: window 0x1e00e9b, revert to Parent number of extensions: 29 BIG-REQUESTS Composite DAMAGE DOUBLE-BUFFER DPMS DRI2 DRI3 GLX Generic Event Extension MIT-SCREEN-SAVER MIT-SHM Present RANDR RECORD RENDER SECURITY SGI-GLX SHAPE SYNC X-Resource XC-MISC XFIXES XFree86-DGA XFree86-VidModeExtension XINERAMA XInputExtension XKEYBOARD XTEST XVideo default screen number: 0 number of screens: 1 screen #0: dimensions: 7680x2160 pixels (2032x572 millimeters) resolution: 96x96 dots per inch depths (7): 24, 1, 4, 8, 15, 16, 32 root window id: 0xe7 depth of root window: 24 planes number of colormaps: minimum 1, maximum 1 default colormap: 0x20 default number of colormap cells: 256 preallocated pixels: black 0, white 16777215 options: backing-store WHEN MAPPED, save-unders NO largest cursor: 256x256 current input event mask: 0xfa4033 KeyPressMask KeyReleaseMask EnterWindowMask LeaveWindowMask KeymapStateMask StructureNotifyMask SubstructureNotifyMask SubstructureRedirectMask FocusChangeMask PropertyChangeMask ColormapChangeMask number of visuals: 40 default visual id: 0x21 visual: visual id: 0x21 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0x22 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xc1 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xc2 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xc3 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xc4 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xc5 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xc6 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xc7 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xc8 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xc9 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xca class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xcb class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xcc class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xcd class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xce class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xcf class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd0 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd1 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd2 class: TrueColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd3 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd4 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd5 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd6 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd7 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd8 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xd9 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xda class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xdb class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xdc class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xdd class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xde class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xdf class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xe0 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xe1 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xe2 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xe3 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xe4 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0xe5 class: DirectColor depth: 24 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits visual: visual id: 0x80 class: TrueColor depth: 32 planes available colormap entries: 256 per subfield red, green, blue masks: 0xff0000, 0xff00, 0xff significant bits in color specification: 8 bits $ xrandr Screen 0: minimum 320 x 200, current 7680 x 2160, maximum 8192 x 8192 VGA-1 connected (normal left inverted right x axis y axis) 1920x1200 59.95 + 1600x1200 60.00 1280x1024 60.02 1280x960 60.00 1024x768 60.00 800x600 60.32 56.25 640x480 59.94 DP-1 disconnected (normal left inverted right x axis y axis) HDMI-1 disconnected (normal left inverted right x axis y axis) DP-1-8 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 621mm x 341mm 3840x2160 29.98*+ 30.00 29.97 1920x1200 59.88 1920x1080 60.00 50.00 59.94 30.00 25.00 24.00 29.97 23.98 1600x1200 60.00 1680x1050 59.95 1280x1024 75.02 60.02 1280x800 59.81 1152x864 75.00 1280x720 60.00 50.00 59.94 1024x768 75.03 60.00 800x600 75.00 60.32 720x576 50.00 720x480 60.00 59.94 640x480 75.00 60.00 59.94 720x400 70.08 DP-1-1-8 connected 3840x2160+3840+0 (normal left inverted right x axis y axis) 621mm x 341mm 3840x2160 29.98*+ 30.00 29.97 1920x1200 59.88 1920x1080 60.00 50.00 59.94 30.00 25.00 24.00 29.97 23.98 1600x1200 60.00 1680x1050 59.95 1280x1024 75.02 60.02 1280x800 59.81 1152x864 75.00 1280x720 60.00 50.00 59.94 1024x768 75.03 60.00 800x600 75.00 60.32 720x576 50.00 720x480 60.00 59.94 640x480 75.00 60.00 59.94 720x400 70.08 DP-1-1-1 disconnected (normal left inverted right x axis y axis) DP-1-1 disconnected (normal left inverted right x axis y axis)