Xrandr, Xscreensaver, and the case of the disappearing modes

michael67 · 11-25-2020, 06:40 PM

I'm running into an odd and annoying problem with xrandr, Xscreensaver, and the resolution my graphics card runs at. Here's my system:

Code:

- Debian 10.5
- HP Compaq 8000 with a Core2 Duo
- Built in graphics controller; from the manual, it appears to be an Intel Q45 GMCH.
- Samsung 4K monitor connected via DisplayPort
- 16 GB RAM
- Mostly running Xscreensaver
- FVWM desktop

On boot, all works well - the monitor is running in 4K (3840x2160). If I lock the display or let the display go to sleep due to inactivity, all works as expected - the monitor goes into standby mode. The problem occurs after I wake up the display.

First, any subsequent locks or waiting for the inactivity time-out for the screensaver to kick in results in a locked display BUT the monitor no goes into standby. Instead the monitor stays on with a black screen.

Second, if I log out of my session, the display is no longer 4K at the login prompt. If I log back in, the display resultion is now 2560x1440.

Finally, xrandr is giving me some weird behavior. I realize that xrandr is just the messenger, and something else is likely going on.

Note that if I do not let the screensaver kick in and I log out and log back in, my resolution is still 4K.

Here's the graphics card info via lspci:

Code:

00:02.0 VGA compatible controller: Intel Corporation 4 Series Chipset Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation 4 Series Chipset Integrated Graphics Controller (rev 03)

Here's the DP-1 snip of the xrandr --verbose when things are good:

Code:

---------------------------------------------------------------------------------------------------------------
DP-1 connected 3840x2160+0+0 (0x45) normal (normal left inverted right x axis y axis) 697mm x 392mm
        Identifier: 0x43
        Timestamp:  19102
        Subpixel:   unknown
        Gamma:      1.0:1.0:1.0
        Brightness: 1.0
        Clones:
        CRTC:       0
        CRTCs:      0 1
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        EDID:
                00ffffffffffff004c2d350f45323930
                1b1e0104b54627783aaea5af4f42af26
                0f5054bfef80714f810081c08180a9c0
                b300950001014dd000a0f0703e803020
                3500b9882100001a000000fd001e4b1e
                873c000a202020202020000000fc0055
                33324a3539780a2020202020000000ff
                004843484e3730323436340a202001b9
                02030ff042105f230907078301000002
                3a801871382d40582c4500b988210000
                1e565e00a0a0a0295030203500b98821
                00001a04740030f2705a80b0588a00b9
                882100001e0000000000000000000000
                00000000000000000000000000000000
                00000000000000000000000000000000
                00000000000000000000000000000056
        Broadcast RGB: Automatic
                supported: Automatic, Full, Limited 16:235
        link-status: Good
                supported: Good, Bad
        CONNECTOR_ID: 61
                supported: 61
        non-desktop: 0
                range: (0, 1)
  3840x2160 (0x45) 297.000MHz +HSync +VSync *current
        h: width  3840 start 4016 end 4104 total 4400 skew    0 clock  67.50KHz
        v: height 2160 start 2168 end 2178 total 2250           clock  30.00Hz
  3840x2160 (0x46) 296.703MHz +HSync +VSync
        h: width  3840 start 4016 end 4104 total 4400 skew    0 clock  67.43KHz
        v: height 2160 start 2168 end 2178 total 2250           clock  29.97Hz
  2560x1440 (0x47) 241.500MHz +HSync -VSync
        h: width  2560 start 2608 end 2640 total 2720 skew    0 clock  88.79KHz
        v: height 1440 start 1443 end 1448 total 1481           clock  59.95Hz
  1920x1080 (0x48) 148.500MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.50KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  60.00Hz
  1920x1080 (0x49) 148.352MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.43KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  59.94Hz
  1680x1050 (0x4a) 146.250MHz -HSync +VSync
        h: width  1680 start 1784 end 1960 total 2240 skew    0 clock  65.29KHz
        v: height 1050 start 1053 end 1059 total 1089           clock  59.95Hz
  1600x900 (0x4b) 108.000MHz +HSync +VSync
        h: width  1600 start 1624 end 1704 total 1800 skew    0 clock  60.00KHz
        v: height  900 start  901 end  904 total 1000           clock  60.00Hz
  1280x1024 (0x4c) 135.000MHz +HSync +VSync
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock  79.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  75.02Hz
  1280x1024 (0x4d) 108.000MHz +HSync +VSync
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock  63.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  60.02Hz
  1440x900 (0x4e) 106.500MHz -HSync +VSync
        h: width  1440 start 1520 end 1672 total 1904 skew    0 clock  55.93KHz
        v: height  900 start  903 end  909 total  934           clock  59.89Hz
  1280x800 (0x4f) 83.500MHz -HSync +VSync
        h: width  1280 start 1352 end 1480 total 1680 skew    0 clock  49.70KHz
        v: height  800 start  803 end  809 total  831           clock  59.81Hz
  1152x864 (0x50) 108.000MHz +HSync +VSync
        h: width  1152 start 1216 end 1344 total 1600 skew    0 clock  67.50KHz
        v: height  864 start  865 end  868 total  900           clock  75.00Hz
  1280x720 (0x51) 74.250MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  45.00KHz
        v: height  720 start  725 end  730 total  750           clock  60.00Hz
  1280x720 (0x52) 74.176MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  44.96KHz
        v: height  720 start  725 end  730 total  750           clock  59.94Hz
  1024x768 (0x53) 78.750MHz +HSync +VSync
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock  60.02KHz
        v: height  768 start  769 end  772 total  800           clock  75.03Hz
  1024x768 (0x54) 75.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1328 skew    0 clock  56.48KHz
        v: height  768 start  771 end  777 total  806           clock  70.07Hz
  1024x768 (0x55) 65.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock  48.36KHz
        v: height  768 start  771 end  777 total  806           clock  60.00Hz
  832x624 (0x56) 57.284MHz -HSync -VSync
        h: width   832 start  864 end  928 total 1152 skew    0 clock  49.73KHz
        v: height  624 start  625 end  628 total  667           clock  74.55Hz
  800x600 (0x57) 50.000MHz +HSync +VSync
        h: width   800 start  856 end  976 total 1040 skew    0 clock  48.08KHz
        v: height  600 start  637 end  643 total  666           clock  72.19Hz
  800x600 (0x58) 49.500MHz +HSync +VSync
        h: width   800 start  816 end  896 total 1056 skew    0 clock  46.88KHz
        v: height  600 start  601 end  604 total  625           clock  75.00Hz
  800x600 (0x59) 40.000MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock  37.88KHz
        v: height  600 start  601 end  605 total  628           clock  60.32Hz
  800x600 (0x5a) 36.000MHz +HSync +VSync
        h: width   800 start  824 end  896 total 1024 skew    0 clock  35.16KHz
        v: height  600 start  601 end  603 total  625           clock  56.25Hz
  640x480 (0x5b) 31.500MHz -HSync -VSync
        h: width   640 start  656 end  720 total  840 skew    0 clock  37.50KHz
        v: height  480 start  481 end  484 total  500           clock  75.00Hz
  640x480 (0x5c) 31.500MHz -HSync -VSync
        h: width   640 start  664 end  704 total  832 skew    0 clock  37.86KHz
        v: height  480 start  489 end  492 total  520           clock  72.81Hz
  640x480 (0x5d) 30.240MHz -HSync -VSync
        h: width   640 start  704 end  768 total  864 skew    0 clock  35.00KHz
        v: height  480 start  483 end  486 total  525           clock  66.67Hz
  640x480 (0x5e) 25.200MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.50KHz
        v: height  480 start  490 end  492 total  525           clock  60.00Hz
  640x480 (0x5f) 25.175MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.47KHz
        v: height  480 start  490 end  492 total  525           clock  59.94Hz
  720x400 (0x60) 28.320MHz -HSync +VSync
        h: width   720 start  738 end  846 total  900 skew    0 clock  31.47KHz
        v: height  400 start  412 end  414 total  449           clock  70.08Hz
---------------------------------------------------------------------------------------------------------------

Here's the DP-1 snip of xrandr --verbose after I lock the screen. There's a couple things to note. First, the 3840x2160 (0x45) entry is at the bottom rather than at the top. Second, "link-status" is now "Bad" rather than "Good" (I couldn't find any documentation on "link-status"); xrandr will not let me change link-status manually:

Code:

---------------------------------------------------------------------------------------------------------------
DP-1 connected 3840x2160+0+0 (0x45) normal (normal left inverted right x axis y axis) 697mm x 392mm
        Identifier: 0x43
        Timestamp:  19102
        Subpixel:   unknown
        Gamma:      1.0:1.0:1.0
        Brightness: 1.0
        Clones:
        CRTC:       0
        CRTCs:      0 1
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        EDID:
                00ffffffffffff004c2d350f45323930
                1b1e0104b54627783aaea5af4f42af26
                0f5054bfef80714f810081c08180a9c0
                b300950001014dd000a0f0703e803020
                3500b9882100001a000000fd001e4b1e
                873c000a202020202020000000fc0055
                33324a3539780a2020202020000000ff
                004843484e3730323436340a202001b9
                02030ff042105f230907078301000002
                3a801871382d40582c4500b988210000
                1e565e00a0a0a0295030203500b98821
                00001a04740030f2705a80b0588a00b9
                882100001e0000000000000000000000
                00000000000000000000000000000000
                00000000000000000000000000000000
                00000000000000000000000000000056
        Broadcast RGB: Automatic
                supported: Automatic, Full, Limited 16:235
        link-status: Bad
                supported: Good, Bad
        CONNECTOR_ID: 61
                supported: 61
        non-desktop: 0
                range: (0, 1)
  2560x1440 (0x47) 241.500MHz +HSync -VSync
        h: width  2560 start 2608 end 2640 total 2720 skew    0 clock  88.79KHz
        v: height 1440 start 1443 end 1448 total 1481           clock  59.95Hz
  1920x1080 (0x48) 148.500MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.50KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  60.00Hz
  1920x1080 (0x49) 148.352MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.43KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  59.94Hz
  1680x1050 (0x4a) 146.250MHz -HSync +VSync
        h: width  1680 start 1784 end 1960 total 2240 skew    0 clock  65.29KHz
        v: height 1050 start 1053 end 1059 total 1089           clock  59.95Hz
  1600x900 (0x4b) 108.000MHz +HSync +VSync
        h: width  1600 start 1624 end 1704 total 1800 skew    0 clock  60.00KHz
        v: height  900 start  901 end  904 total 1000           clock  60.00Hz
  1280x1024 (0x4c) 135.000MHz +HSync +VSync
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock  79.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  75.02Hz
  1280x1024 (0x4d) 108.000MHz +HSync +VSync
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock  63.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  60.02Hz
  1440x900 (0x4e) 106.500MHz -HSync +VSync
        h: width  1440 start 1520 end 1672 total 1904 skew    0 clock  55.93KHz
        v: height  900 start  903 end  909 total  934           clock  59.89Hz
  1280x800 (0x4f) 83.500MHz -HSync +VSync
        h: width  1280 start 1352 end 1480 total 1680 skew    0 clock  49.70KHz
        v: height  800 start  803 end  809 total  831           clock  59.81Hz
  1152x864 (0x50) 108.000MHz +HSync +VSync
        h: width  1152 start 1216 end 1344 total 1600 skew    0 clock  67.50KHz
        v: height  864 start  865 end  868 total  900           clock  75.00Hz
  1280x720 (0x51) 74.250MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  45.00KHz
        v: height  720 start  725 end  730 total  750           clock  60.00Hz
  1280x720 (0x52) 74.176MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  44.96KHz
        v: height  720 start  725 end  730 total  750           clock  59.94Hz
  1024x768 (0x53) 78.750MHz +HSync +VSync
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock  60.02KHz
        v: height  768 start  769 end  772 total  800           clock  75.03Hz
  1024x768 (0x54) 75.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1328 skew    0 clock  56.48KHz
        v: height  768 start  771 end  777 total  806           clock  70.07Hz
  1024x768 (0x55) 65.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock  48.36KHz
        v: height  768 start  771 end  777 total  806           clock  60.00Hz
  832x624 (0x56) 57.284MHz -HSync -VSync
        h: width   832 start  864 end  928 total 1152 skew    0 clock  49.73KHz
        v: height  624 start  625 end  628 total  667           clock  74.55Hz
  800x600 (0x57) 50.000MHz +HSync +VSync
        h: width   800 start  856 end  976 total 1040 skew    0 clock  48.08KHz
        v: height  600 start  637 end  643 total  666           clock  72.19Hz
  800x600 (0x58) 49.500MHz +HSync +VSync
        h: width   800 start  816 end  896 total 1056 skew    0 clock  46.88KHz
        v: height  600 start  601 end  604 total  625           clock  75.00Hz
  800x600 (0x59) 40.000MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock  37.88KHz
        v: height  600 start  601 end  605 total  628           clock  60.32Hz
  800x600 (0x5a) 36.000MHz +HSync +VSync
        h: width   800 start  824 end  896 total 1024 skew    0 clock  35.16KHz
        v: height  600 start  601 end  603 total  625           clock  56.25Hz
  640x480 (0x5b) 31.500MHz -HSync -VSync
        h: width   640 start  656 end  720 total  840 skew    0 clock  37.50KHz
        v: height  480 start  481 end  484 total  500           clock  75.00Hz
  640x480 (0x5c) 31.500MHz -HSync -VSync
        h: width   640 start  664 end  704 total  832 skew    0 clock  37.86KHz
        v: height  480 start  489 end  492 total  520           clock  72.81Hz
  640x480 (0x5d) 30.240MHz -HSync -VSync
        h: width   640 start  704 end  768 total  864 skew    0 clock  35.00KHz
        v: height  480 start  483 end  486 total  525           clock  66.67Hz
  640x480 (0x5e) 25.200MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.50KHz
        v: height  480 start  490 end  492 total  525           clock  60.00Hz
  640x480 (0x5f) 25.175MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.47KHz
        v: height  480 start  490 end  492 total  525           clock  59.94Hz
  720x400 (0x60) 28.320MHz -HSync +VSync
        h: width   720 start  738 end  846 total  900 skew    0 clock  31.47KHz
        v: height  400 start  412 end  414 total  449           clock  70.08Hz
  3840x2160 (0x45) 297.000MHz +HSync +VSync
        h: width  3840 start 4016 end 4104 total 4400 skew    0 clock  67.50KHz
        v: height 2160 start 2168 end 2178 total 2250           clock  30.00Hz
---------------------------------------------------------------------------------------------------------------

For fun I tried to set the output to mode 0x45:
---------------------------------------------------------------------------------------------------------------
~$ xrandr --output DP-1 --mode 0x45
xrandr: cannot find mode 0x45
~$
---------------------------------------------------------------------------------------------------------------

Very odd. If I log out and log back in to FVWM, the old 0x45 is gone and 2560x1440 is now 0x45:

Code:

--------------------------------------------------------------------------------------------------------------- 
DP-1 connected 2560x1440+0+0 (0x45) normal (normal left inverted right x axis y axis) 697mm x 392mm
        Identifier: 0x43
        Timestamp:  1220956
        Subpixel:   unknown
        Gamma:      1.0:1.0:1.0
        Brightness: 1.0
        Clones:
        CRTC:       0
        CRTCs:      0 1
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        EDID:
                00ffffffffffff004c2d350f45323930
                1b1e0104b54627783aaea5af4f42af26
                0f5054bfef80714f810081c08180a9c0
                b300950001014dd000a0f0703e803020
                3500b9882100001a000000fd001e4b1e
                873c000a202020202020000000fc0055
                33324a3539780a2020202020000000ff
                004843484e3730323436340a202001b9
                02030ff042105f230907078301000002
                3a801871382d40582c4500b988210000
                1e565e00a0a0a0295030203500b98821
                00001a04740030f2705a80b0588a00b9
                882100001e0000000000000000000000
                00000000000000000000000000000000
                00000000000000000000000000000000
                00000000000000000000000000000056
        Broadcast RGB: Automatic
                supported: Automatic, Full, Limited 16:235
        link-status: Good
                supported: Good, Bad
        CONNECTOR_ID: 61
                supported: 61
        non-desktop: 0
                range: (0, 1)
  2560x1440 (0x45) 241.500MHz +HSync -VSync *current
        h: width  2560 start 2608 end 2640 total 2720 skew    0 clock  88.79KHz
        v: height 1440 start 1443 end 1448 total 1481           clock  59.95Hz
  1920x1080 (0x46) 148.500MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.50KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  60.00Hz
  1920x1080 (0x47) 148.352MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.43KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  59.94Hz
  1680x1050 (0x48) 146.250MHz -HSync +VSync
        h: width  1680 start 1784 end 1960 total 2240 skew    0 clock  65.29KHz
        v: height 1050 start 1053 end 1059 total 1089           clock  59.95Hz
  1600x900 (0x49) 108.000MHz +HSync +VSync
        h: width  1600 start 1624 end 1704 total 1800 skew    0 clock  60.00KHz
        v: height  900 start  901 end  904 total 1000           clock  60.00Hz
  1280x1024 (0x4a) 135.000MHz +HSync +VSync
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock  79.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  75.02Hz
  1280x1024 (0x4b) 108.000MHz +HSync +VSync
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock  63.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  60.02Hz
  1440x900 (0x4c) 106.500MHz -HSync +VSync
        h: width  1440 start 1520 end 1672 total 1904 skew    0 clock  55.93KHz
        v: height  900 start  903 end  909 total  934           clock  59.89Hz
  1280x800 (0x4d) 83.500MHz -HSync +VSync
        h: width  1280 start 1352 end 1480 total 1680 skew    0 clock  49.70KHz
        v: height  800 start  803 end  809 total  831           clock  59.81Hz
  1152x864 (0x4e) 108.000MHz +HSync +VSync
        h: width  1152 start 1216 end 1344 total 1600 skew    0 clock  67.50KHz
        v: height  864 start  865 end  868 total  900           clock  75.00Hz
  1280x720 (0x4f) 74.250MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  45.00KHz
        v: height  720 start  725 end  730 total  750           clock  60.00Hz
  1280x720 (0x50) 74.176MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  44.96KHz
        v: height  720 start  725 end  730 total  750           clock  59.94Hz
  1024x768 (0x51) 78.750MHz +HSync +VSync
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock  60.02KHz
        v: height  768 start  769 end  772 total  800           clock  75.03Hz
  1024x768 (0x52) 75.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1328 skew    0 clock  56.48KHz
        v: height  768 start  771 end  777 total  806           clock  70.07Hz
  1024x768 (0x53) 65.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock  48.36KHz
        v: height  768 start  771 end  777 total  806           clock  60.00Hz
  832x624 (0x54) 57.284MHz -HSync -VSync
        h: width   832 start  864 end  928 total 1152 skew    0 clock  49.73KHz
        v: height  624 start  625 end  628 total  667           clock  74.55Hz
  800x600 (0x55) 50.000MHz +HSync +VSync
        h: width   800 start  856 end  976 total 1040 skew    0 clock  48.08KHz
        v: height  600 start  637 end  643 total  666           clock  72.19Hz
  800x600 (0x56) 49.500MHz +HSync +VSync
        h: width   800 start  816 end  896 total 1056 skew    0 clock  46.88KHz
        v: height  600 start  601 end  604 total  625           clock  75.00Hz
  800x600 (0x57) 40.000MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock  37.88KHz
        v: height  600 start  601 end  605 total  628           clock  60.32Hz
  800x600 (0x58) 36.000MHz +HSync +VSync
        h: width   800 start  824 end  896 total 1024 skew    0 clock  35.16KHz
        v: height  600 start  601 end  603 total  625           clock  56.25Hz
  640x480 (0x59) 31.500MHz -HSync -VSync
        h: width   640 start  656 end  720 total  840 skew    0 clock  37.50KHz
        v: height  480 start  481 end  484 total  500           clock  75.00Hz
  640x480 (0x5a) 31.500MHz -HSync -VSync
        h: width   640 start  664 end  704 total  832 skew    0 clock  37.86KHz
        v: height  480 start  489 end  492 total  520           clock  72.81Hz
  640x480 (0x5b) 30.240MHz -HSync -VSync
        h: width   640 start  704 end  768 total  864 skew    0 clock  35.00KHz
        v: height  480 start  483 end  486 total  525           clock  66.67Hz
  640x480 (0x5c) 25.200MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.50KHz
        v: height  480 start  490 end  492 total  525           clock  60.00Hz
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.47KHz
        v: height  480 start  490 end  492 total  525           clock  59.94Hz
  720x400 (0x5e) 28.320MHz -HSync +VSync
        h: width   720 start  738 end  846 total  900 skew    0 clock  31.47KHz
        v: height  400 start  412 end  414 total  449           clock  70.08Hz
---------------------------------------------------------------------------------------------------------------

I can repeat these steps (lock screen, unlock screen, log out, log in) for the new resolution, causing 2560x1440 to also disappear. This knocks me back to 1920x1080. As before, 0x45 is not recognized once I lock the screen and let it go to sleep.

Trying to re-create the original mode via xrandr gives me an error:

Code:

---------------------------------------------------------------------------------------------------------------
 ~$ xrandr --newmode "3840x2160_30.00"  338.75  3840 4080 4488 5136  2160 2163 2168 2200 -hsync +vsync
 ~$ xrandr --addmode DP-1 3840x2160_30.00
 ~$ xrandr --output DP-1 --mode "3840x2160_30.00"
xrandr: Configure crtc 0 failed
 ~$
---------------------------------------------------------------------------------------------------------------

Any thoughts on where to start looking? I know it's an older system.

Thanks in advance,
Michael

business_kid · 11-26-2020, 07:26 AM

Your video card appears to be an 82Q45, which intel released in 2008.
I by comparison have a HD4000 graphics card from 2012 and I think that sucks. I certainly wouldn't put a 4Kmonitor on it. The HDMI 2.0 standard wasn't released until 2015.

My advice to you is the same as my advice to myself: Use hdmi 1 = 1920x1080

michael67 · 11-26-2020, 08:25 PM

Quote:

Originally Posted by business_kid

Your video card appears to be an 82Q45, which intel released in 2008.
I by comparison have a HD4000 graphics card from 2012 and I think that sucks. I certainly wouldn't put a 4Kmonitor on it. The HDMI 2.0 standard wasn't released until 2015.

My advice to you is the same as my advice to myself: Use hdmi 1 = 1920x1080

I figured it was about that era. I'm using the Display Port, not HDMI. I was a bit surprised it worked, as prior to my taking possession it was running Windows 10. Hooking up the 4k monitor with Windows 10 caused a continual failure on Windows 10 - Windows 10 constantly tried and failed to set a resolution. At least I can use a 4k monitor under Linux, albeit with the aforementioned (relatively minor) issue.

I'll probably end up buying a new video card at some point. In the mean time, I'll stick with the built in and hope for someone to point me towards a possible solution.

Thanks.

business_kid · 11-27-2020, 12:50 PM

I pointed you at a solution. Use hdmi 1.0 = 1920x1080.

With that card, any attempt to set 4K will give crap video, as in lousy refresh rates. On my thing with comparatively better performance, I once ran 1600x900 on one screen, & 1280x768 on another for a Seminar. It barely kept lip sync, that is the speaker's lips barely kept up with what he said (90% of the time or so). There was speakers, so the background was still.

There's online tests you can run, also xrandr.

michael67 · 11-27-2020, 09:00 PM

Perhaps I did not explain the problem. The problem is not with the display itself - the on-board graphics drives the 4k monitor at 4k without a problem. Perhaps if I was into games or something that required fast refresh then the on-board graphics hardware would be insufficient, but for what I use it for I'm perfectly happy with the quality of the display. I see no flicker or artifacts. I'm able to drag windows all of the display or resize to any size without anything odd happening.

The problem is primarily with the sleep mode of the DisplayPort output. As long as I do not log out, the display is still driven at 4K. So again, this is more of an annoyance in that I don't really have a monitor sleep mode and I must manually shut off the monitor if I step away for any period of time.

business_kid · 11-28-2020, 06:21 AM

So if you're not phased by an inability to watch video, then fine, go with 4k.

In your gui power manager, you can usually set up that stuff

Disable 'standby.' It uses 99% of the power and only annoys you. If you use mains 100% of the time, you can disable suspend. Suspend really is for laptops on battery power. Hibernate takes nearly as long as power off time wise, so that could go too, and just use a screensaver.