Intel Arc A750 improperly reading/applying EDID?

I seem to be struggling a bit with a transition from an nVidia GTX1650 to an Intel Arc A750.

The A750 appears to boot fine in eOS (in Xfce), but has constantly been giving me issues with my display (LG Ultrawide 29WK500). I have been unable to use the 2560x1080 resolution in any respect on the display which was not an issue with the GTX1650 (it detected and allowed the resolution without any issues).

xrandr is clearly not showing this mode as detected:

$ xrandr -q

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
HDMI-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 798mm x 334mm
   1920x1080     60.00*   50.00    59.94
   1680x1050     59.88
   1600x900      60.00
   1280x1024     75.02    60.02
   1280x800      59.91
   1152x864      75.00
   1280x720      60.00    50.00    59.94
   1024x768      75.03    60.00
   832x624       74.55
   800x600       75.00    60.32
   720x576       50.00
   720x480       60.00    59.94
   640x480       75.00    60.00    59.94

Reading the EDID from the display clearly shows the resolutions (and its supported 60 and 75 Hz refresh rates) in the DTDs:


$ edid-decode /sys/class/drm/card1-HDMI-A-1/edid
--------
00 ff ff ff ff ff ff 00 1e 6d f9 76 5f db 06 00
01 1d 01 03 80 50 22 78 ea ca 95 a6 55 4e a1 26
0f 50 54 25 6b 80 71 40 81 80 81 c0 a9 c0 b3 00
d1 c0 81 00 d1 cf cd 46 00 a0 a0 38 1f 40 30 20
3a 00 1e 4e 31 00 00 1a 00 3a 80 18 71 38 2d 40
58 2c 45 00 13 2a 21 00 00 1e 00 00 00 fd 00 28
4b 5a 5a 18 00 0a 20 20 20 20 20 20 00 00 00 fc
00 4c 47 20 55 4c 54 52 41 57 49 44 45 0a 01 9a

02 03 23 f1 23 09 07 07 47 10 04 03 01 1f 13 12
83 01 00 00 65 03 0c 00 20 00 68 1a 00 00 01 01
28 4b 00 8c 0a d0 8a 20 e0 2d 10 10 3e 96 00 1e
4e 31 00 00 18 29 59 00 a0 a0 38 27 40 30 20 3a
00 1e 4e 31 00 00 1a 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 93
--------
Block 0, Base EDID:

  Detailed Timing Descriptors:
    DTD 1:  2560x1080   59.978424 Hz  64:27    66.636 kHz    181.250000 MHz (798 mm x 334 mm)
                 Hfront   48 Hsync  32 Hback   80 Hpol P
                 Vfront    3 Vsync  10 Vback   18 Vpol N
    DTD 2:  1920x1080   59.991919 Hz  16:9     67.491 kHz    148.480000 MHz (531 mm x 298 mm)
                 Hfront   88 Hsync  44 Hback  148 Hpol P
                 Vfront    4 Vsync   5 Vback   36 Vpol P
    Display Range Limits:
      Monitor ranges (GTF): 40-75 Hz V, 90-90 kHz H, max dotclock 240 MHz
    Display Product Name: 'LG ULTRAWIDE'
[…]
Block 1, CTA-861 Extension Block:

  Detailed Timing Descriptors:
    DTD 3:   720x480    59.940060 Hz   3:2     31.469 kHz     27.000000 MHz (798 mm x 334 mm)
                 Hfront   16 Hsync  62 Hback   60 Hpol N
                 Vfront    9 Vsync   6 Vback   30 Vpol N
    DTD 4:  2560x1080   74.991458 Hz  64:27    83.915 kHz    228.250000 MHz (798 mm x 334 mm)
                 Hfront   48 Hsync  32 Hback   80 Hpol P
                 Vfront    3 Vsync  10 Vback   26 Vpol N

I’ve tried to force the resolutions on xrandr using the DTD details to no avail.

$ xrandr --newmode "2560x1080@60" 181.25 2560 2608 2640 2720 1080 1083 1093 1111 +hsync -vsync
$ xrandr --addmode HDMI-1 2560x1080@60
$ xrandr --output HDMI-1 --mode 2560x1080@60
$ xrandr --output HDMI-1 --mode 2560x1080@60 --verbose
screen 0: 2560x1080 677x286 mm  95.92dpi
crtc 0: 2560x1080@60  59.98 +0+0 "HDMI-1"
xrandr: Configure crtc 0 failed
crtc 0: disable
crtc 1: disable
crtc 2: disable
crtc 3: disable
screen 0: revert
crtc 0: revert
crtc 1: revert
crtc 2: revert
crtc 3: revert
$ xrandr --newmode "2560x1080@75" 228.25 2560 2608 2640 2720 1080 1083 1093 1119 +hsync -vsync
$ xrandr --addmode HDMI-1 2560x1080@75
$ xrandr --output HDMI-1 --mode 2560x1080@75
$ xrandr --output HDMI-1 --mode 2560x1080@75 --verbose
screen 0: 2560x1080 677x286 mm  95.92dpi
crtc 0: 2560x1080@75  74.99 +0+0 "HDMI-1"
xrandr: Configure crtc 0 failed
crtc 0: disable
crtc 1: disable
crtc 2: disable
crtc 3: disable
screen 0: revert
crtc 0: revert
crtc 1: revert
crtc 2: revert
crtc 3: revert

I get the same behavior if I attempt to use DP->HDMI instead (at least from the first DP port; I haven’t tested the other two yet).

I get the same behavior attempting to boot into Gnome, or even booting Gnome and Xfce live ISOs of Fedora.

The display is detected without issue and available resolutions are presented in Windows 10 on the same machine just fine, so this seems to be restricted to eOS (or the 6.6/6.11 kernels at the very least as I’ve tried booting both the standard and LTS kernels).

I also have issues with GPU hangups while playing Minecraft, but any gaming issues are sort of secondary to resolving the resolution detection/presentation display issue (so I can at least resume my standard productivity work during the day).

Oddly, when I connect a second standard 1080p display at the same time, the second display (a Dell P2217H) registers the exact same name in xfce4-display-settings (as LG Electronics 34") and shows the missing 2560x1080 resolution (but is only attempting to apply it to the Dell display if I choose).

If anyone has some tips on where to go with this or what else to explore, I would greatly appreciate the assistance. I’ve anecdotally seen mention that EDID detection is not great on Arc, but that was at least a few months ago and I have no idea where things stand presently.

What does this show? You may need to install hwinfo

 sudo hwinfo --monitor

Edit: You could install read-edid and run

get-edid | parse-edid

Edit: Maybe this helps you at least show what it supports.

welcome @cjb here :enos:
i have the same ARC 750 but no widescreen display only some 1920x1080 displays connected via DP… in holidays at the moment so no way to check anything with it.


https://www.intel.com/content/www/us/en/products/sku/227954/intel-arc-a750-graphics/specifications.html

hwinfo sees the correct information:

$ sudo hwinfo --monitor
50: None 00.0: 10002 LCD Monitor
  [Created at monitor.125]
  Unique ID: rdCR.nycPUrCKFzE
  Parent ID: svHJ.iZZ3J3xguL2
  Hardware Class: monitor
  Model: "LG ELECTRONICS LG ULTRAWIDE"
  Vendor: GSM "LG ELECTRONICS"
  Device: eisa 0x76f9 "LG ULTRAWIDE"
  Serial ID: "449375"
  Resolution: 640x480@60Hz
  Resolution: 640x480@75Hz
  Resolution: 800x600@60Hz
  Resolution: 800x600@75Hz
  Resolution: 832x624@75Hz
  Resolution: 1024x768@60Hz
  Resolution: 1024x768@75Hz
  Resolution: 1280x1024@75Hz
  Resolution: 1152x864@60Hz
  Resolution: 1280x1024@60Hz
  Resolution: 1280x720@60Hz
  Resolution: 1600x900@60Hz
  Resolution: 1920x1080@60Hz
  Resolution: 2560x1080@60Hz
  Size: 531x298 mm
  Year of Manufacture: 2019
  Week of Manufacture: 1
  Detailed Timings #0:
     Resolution: 2560x1080
     Horizontal: 2560 2608 2640 2720 (+48 +80 +160) -hsync
       Vertical: 1080 1083 1093 1111 (+3 +13 +31) +vsync
    Frequencies: 181.25 MHz, 66.64 kHz, 59.98 Hz
  Year of Manufacture: 2019
  Week of Manufacture: 1
  Detailed Timings #1:
     Resolution: 1920x1080
     Horizontal: 1920 2008 2052 2200 (+88 +132 +280) +hsync
       Vertical: 1080 1084 1089 1125 (+4 +9 +45) +vsync
    Frequencies: 148.48 MHz, 67.49 kHz, 59.99 Hz
  Driver Info #0:
    Max. Resolution: 2560x1080
    Vert. Sync Range: 40-75 Hz
    Hor. Sync Range: 90-90 kHz
    Bandwidth: 181 MHz
  Config Status: cfg=new, avail=yes, need=no, active=unknown
  Attached to: #7 (VGA compatible controller)

I’ve already tried to go the get-edid route to no avail:

$ sudo get-edid
sudo get-edid
This is read-edid version 3.0.2. Prepare for some fun.
Attempting to use i2c interface
Looks like no busses have an EDID. Sorry!
Attempting to use the classical VBE interface

	Performing real mode VBE call
	Interrupt 0x10 ax=0x4f00 bx=0x0 cx=0x0
	Function unsupported
	Call failed

	VBE version 0
	VBE string at 0x0 "O"

VBE/DDC service about to be called
	Report DDC capabilities

	Performing real mode VBE call
	Interrupt 0x10 ax=0x4f15 bx=0x0 cx=0x0
	Function unsupported
	Call failed

Reading next EDID block

VBE/DDC service about to be called
	Read EDID

	Performing real mode VBE call
	Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
	Function unsupported
	Call failed

The EDID data should not be trusted as the VBE call failed
Error: output block unchanged
I'm sorry nothing was successful. Maybe try some other arguments
if you played with them, or send an email to Matthew Kern <pyrophobicman@gmail.com>.

As there’s nothing there, piping into parse-edid obviously doesn’t do anything. I can pipe /sys/class/drm/${INTERFACE}/edid into parse-edid and then get the following:

$ parse-edid < /sys/class/drm/card1-HDMI-A-1/edid
parse-edid < /sys/class/drm/card1-HDMI-A-1/edid
Checksum Correct

Section "Monitor"
	Identifier "LG ULTRAWIDE"
	ModelName "LG ULTRAWIDE"
	VendorName "GSM"
	# Monitor Manufactured week 1 of 2019
	# EDID version 1.3
	# Digital Display
	DisplaySize 800 340
	Gamma 2.20
	Option "DPMS" "true"
	Horizsync 90-90
	VertRefresh 40-75
	# Maximum pixel clock is 240MHz
	#Not giving standard mode: 1152x864, 60Hz
	#Not giving standard mode: 1280x1024, 60Hz
	#Not giving standard mode: 1280x720, 60Hz
	#Not giving standard mode: 1600x900, 60Hz
	#Not giving standard mode: 1680x1050, 60Hz
	#Not giving standard mode: 1920x1080, 60Hz
	#Not giving standard mode: 1280x800, 60Hz
	#Not giving standard mode: 1920x1080, 75Hz

	#Extension block found. Parsing...
extb[4]: 0x23 (0x20)
Hmm, you have data blocks, but not video ones... weird
Something strange happened. Please contact the author,
Matthew Kern at <pyrophobicman@gmail.com>

…which would be fine if it was only Block 0 since DTD 1 is the full resolution at only 60Hz. Only DTDs 3 and 4 (full res at 75Hz) are in the CTA-861 Extension block. But edid-decode as I demonstrated in my original post can parse out the EDID unlike parse-edid.

I know it’s not a limitation to the card: it works exactly as expected booting into Windows 10 on the same machine, full resolution (2560x1080) and refresh rate (both 60 and 75 Hz) that the monitor is spec’d for.

It should also be noted that Xorg sees the correct resolutions presented to it via DDC when probing the resolutions with xrandr -q.

$ tail -n28 /var/log/Xorg.log.0
[  1469.331] (II) modeset(0): EDID vendor "GSM", prod id 30457
[  1469.331] (II) modeset(0): Using hsync ranges from config file
[  1469.331] (II) modeset(0): Using vrefresh ranges from config file
[  1469.331] (II) modeset(0): Printing DDC gathered Modelines:
[  1469.331] (II) modeset(0): Modeline "2560x1080"x0.0  181.25  2560 2608 2640 2720  1080 1083 1093 1111 +hsync -vsync (66.6 kHz eP)
[  1469.331] (II) modeset(0): Modeline "1920x1080"x0.0  148.48  1920 2008 2052 2200  1080 1084 1089 1125 +hsync +vsync (67.5 kHz e)
[  1469.331] (II) modeset(0): Modeline "720x480"x0.0   27.00  720 736 798 858  480 489 495 525 -hsync -vsync (31.5 kHz e)
[  1469.331] (II) modeset(0): Modeline "2560x1080"x0.0  228.25  2560 2608 2640 2720  1080 1083 1093 1119 +hsync -vsync (83.9 kHz e)
[  1469.331] (II) modeset(0): Modeline "1920x1080"x0.0  148.50  1920 2008 2052 2200  1080 1084 1089 1125 +hsync +vsync (67.5 kHz e)
[  1469.331] (II) modeset(0): Modeline "1280x720"x0.0   74.25  1280 1390 1430 1650  720 725 730 750 +hsync +vsync (45.0 kHz e)
[  1469.331] (II) modeset(0): Modeline "640x480"x0.0   25.18  640 656 752 800  480 490 492 525 -hsync -vsync (31.5 kHz e)
[  1469.331] (II) modeset(0): Modeline "1920x1080"x0.0  148.50  1920 2448 2492 2640  1080 1084 1089 1125 +hsync +vsync (56.2 kHz e)
[  1469.331] (II) modeset(0): Modeline "1280x720"x0.0   74.25  1280 1720 1760 1980  720 725 730 750 +hsync +vsync (37.5 kHz e)
[  1469.331] (II) modeset(0): Modeline "720x576"x0.0   27.00  720 732 796 864  576 581 586 625 -hsync -vsync (31.2 kHz e)
[  1469.331] (II) modeset(0): Modeline "800x600"x0.0   40.00  800 840 968 1056  600 601 605 628 +hsync +vsync (37.9 kHz e)
[  1469.331] (II) modeset(0): Modeline "640x480"x0.0   31.50  640 656 720 840  480 481 484 500 -hsync -vsync (37.5 kHz e)
[  1469.331] (II) modeset(0): Modeline "1280x1024"x0.0  135.00  1280 1296 1440 1688  1024 1025 1028 1066 +hsync +vsync (80.0 kHz e)
[  1469.331] (II) modeset(0): Modeline "1024x768"x0.0   78.75  1024 1040 1136 1312  768 769 772 800 +hsync +vsync (60.0 kHz e)
[  1469.331] (II) modeset(0): Modeline "1024x768"x0.0   65.00  1024 1048 1184 1344  768 771 777 806 -hsync -vsync (48.4 kHz e)
[  1469.331] (II) modeset(0): Modeline "832x624"x0.0   57.28  832 864 928 1152  624 625 628 667 -hsync -vsync (49.7 kHz e)
[  1469.331] (II) modeset(0): Modeline "800x600"x0.0   49.50  800 816 896 1056  600 601 604 625 +hsync +vsync (46.9 kHz e)
[  1469.331] (II) modeset(0): Modeline "1152x864"x0.0  108.00  1152 1216 1344 1600  864 865 868 900 +hsync +vsync (67.5 kHz e)
[  1469.331] (II) modeset(0): Modeline "1152x864"x60.0   81.62  1152 1216 1336 1520  864 865 868 895 -hsync +vsync (53.7 kHz e)
[  1469.331] (II) modeset(0): Modeline "1280x1024"x0.0  108.00  1280 1328 1440 1688  1024 1025 1028 1066 +hsync +vsync (64.0 kHz e)
[  1469.331] (II) modeset(0): Modeline "1600x900"x60.0  119.00  1600 1696 1864 2128  900 901 904 932 -hsync +vsync (55.9 kHz e)
[  1469.331] (II) modeset(0): Modeline "1680x1050"x0.0  119.00  1680 1728 1760 1840  1050 1053 1059 1080 +hsync -vsync (64.7 kHz e)
[  1469.331] (II) modeset(0): Modeline "1280x800"x0.0   71.00  1280 1328 1360 1440  800 803 809 823 +hsync -vsync (49.3 kHz e)
[  1469.331] (II) modeset(0): Modeline "1920x1080"x75.0  220.64  1920 2056 2264 2608  1080 1081 1084 1128 -hsync +vsync (84.6 kHz e)

But again, as I showed above in the original post, forcibly adding these modelines to xrandr manually and then attempting to set output to the new mode fails (only a black blip) before returning to the original resolution.

So I’ve booted over to Win10 and stripped the EDID information out of there while in the max resolution.

Monitor #1 [Real-time 0x0100]
  Model name............... LG ULTRAWIDE
  Manufacturer............. LGE
  Plug and Play ID......... GSM76F9
  Serial number............ 449375
  Manufacture date......... 2019, ISO week 1
  Filter driver............ None
  -------------------------
  EDID revision............ 1.3
  Input signal type........ Digital
  Color bit depth.......... Undefined
  Display type............. RGB color
  Screen size.............. 800 x 340 mm (34.2 in)
  Power management......... Standby, Suspend, Active off/sleep
  Extension blocs.......... 1 (Unknown type)
  -------------------------
  DDC/CI................... Supported
  MCCS revison............. 2.1
  Display technology....... TFT
  Controller............... RealTek 0xFF00
  Firmware revision........ 3.6
  Firmware flags........... 0x00FF0068
  Active power on time..... 32140 hours
  Power consumption........ 6.55 kWh
  Current frequency........ 83.90kHz, 83.90Hz

Color characteristics
  Default color space...... Non-sRGB
  Display gamma............ 2.20
  Red chromaticity......... Rx 0.651 - Ry 0.332
  Green chromaticity....... Gx 0.307 - Gy 0.631
  Blue chromaticity........ Bx 0.150 - By 0.060
  White point (default).... Wx 0.313 - Wy 0.329
  Additional descriptors... None

Timing characteristics
  Horizontal scan range.... 90-90kHz
  Vertical scan range...... 40-75Hz
  Video bandwidth.......... 240MHz
  CVT standard............. Not supported
  GTF standard............. Not supported
  Additional descriptors... None
  Preferred timing......... Yes
  Native/preferred timing.. 2560x1080p at 60Hz 
    Modeline............... "2560x1080" 181.250 2560 2608 2640 2720 1080 1083 1093 1111 +hsync -vsync
  Detailed timing #1....... 1920x1080p at 60Hz (16:9)
    Modeline............... "1920x1080" 148.480 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync

Standard timings supported
     640 x  480p at  60Hz - IBM VGA
     640 x  480p at  75Hz - VESA
     800 x  600p at  60Hz - VESA
     800 x  600p at  75Hz - VESA
     832 x  624p at  75Hz - Apple Mac II
    1024 x  768p at  60Hz - VESA
    1024 x  768p at  75Hz - VESA
    1280 x 1024p at  75Hz - VESA
    1152 x  870p at  75Hz - Apple Mac II
    1152 x  864p at  60Hz - VESA STD
    1280 x 1024p at  60Hz - VESA STD
    1280 x  720p at  60Hz - VESA STD
    1600 x  900p at  60Hz - VESA STD
    1680 x 1050p at  60Hz - VESA STD
    1920 x 1080p at  60Hz - VESA STD
    1280 x  800p at  60Hz - VESA STD
    1920 x 1080p at  75Hz - VESA STD

Report information
  Date generated........... 10/26/2024
  Software revision........ 2.90.0.996
  Data source.............. Real-time 0x0100
  Operating system......... 6.2.9200.2

Raw data
  00,FF,FF,FF,FF,FF,FF,00,1E,6D,F9,76,5F,DB,06,00,01,1D,01,03,80,50,22,78,EA,CA,95,A6,55,4E,A1,26,
  0F,50,54,25,6B,80,71,40,81,80,81,C0,A9,C0,B3,00,D1,C0,81,00,D1,CF,CD,46,00,A0,A0,38,1F,40,30,20,
  3A,00,1E,4E,31,00,00,1A,00,3A,80,18,71,38,2D,40,58,2C,45,00,13,2A,21,00,00,1E,00,00,00,FD,00,28,
  4B,5A,5A,18,00,0A,20,20,20,20,20,20,00,00,00,FC,00,4C,47,20,55,4C,54,52,41,57,49,44,45,0A,01,9A

---------------------------

The EDID is virtually identical except for a minor difference in the CTA-861 extension block.

$ diff -y lin.out win.out
edid-decode (hex):						edid-decode (hex):

00 ff ff ff ff ff ff 00 1e 6d f9 76 5f db 06 00			00 ff ff ff ff ff ff 00 1e 6d f9 76 5f db 06 00
01 1d 01 03 80 50 22 78 ea ca 95 a6 55 4e a1 26			01 1d 01 03 80 50 22 78 ea ca 95 a6 55 4e a1 26
0f 50 54 25 6b 80 71 40 81 80 81 c0 a9 c0 b3 00			0f 50 54 25 6b 80 71 40 81 80 81 c0 a9 c0 b3 00
d1 c0 81 00 d1 cf cd 46 00 a0 a0 38 1f 40 30 20			d1 c0 81 00 d1 cf cd 46 00 a0 a0 38 1f 40 30 20
3a 00 1e 4e 31 00 00 1a 00 3a 80 18 71 38 2d 40			3a 00 1e 4e 31 00 00 1a 00 3a 80 18 71 38 2d 40
58 2c 45 00 13 2a 21 00 00 1e 00 00 00 fd 00 28			58 2c 45 00 13 2a 21 00 00 1e 00 00 00 fd 00 28
4b 5a 5a 18 00 0a 20 20 20 20 20 20 00 00 00 fc			4b 5a 5a 18 00 0a 20 20 20 20 20 20 00 00 00 fc
00 4c 47 20 55 4c 54 52 41 57 49 44 45 0a 01 9a			00 4c 47 20 55 4c 54 52 41 57 49 44 45 0a 01 9a

02 03 23 f1 23 09 07 07 47 10 04 03 01 1f 13 12			02 03 23 f1 23 09 07 07 47 10 04 03 01 1f 13 12
83 01 00 00 65 03 0c 00 20 00 68 1a 00 00 01 01		      |	83 01 00 00 65 03 0c 00 10 00 68 1a 00 00 01 01
28 4b 00 8c 0a d0 8a 20 e0 2d 10 10 3e 96 00 1e			28 4b 00 8c 0a d0 8a 20 e0 2d 10 10 3e 96 00 1e
4e 31 00 00 18 29 59 00 a0 a0 38 27 40 30 20 3a			4e 31 00 00 18 29 59 00 a0 a0 38 27 40 30 20 3a
00 1e 4e 31 00 00 1a 00 00 00 00 00 00 00 00 00			00 1e 4e 31 00 00 1a 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00			00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00			00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 93		      |	00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 a3

----------------						----------------

Block 0, Base EDID:						Block 0, Base EDID:
  EDID Structure Version & Revision: 1.3			  EDID Structure Version & Revision: 1.3
  Vendor & Product Identification:				  Vendor & Product Identification:
    Manufacturer: GSM						    Manufacturer: GSM
    Model: 30457						    Model: 30457
    Serial Number: 449375 (0x0006db5f)				    Serial Number: 449375 (0x0006db5f)
    Made in: week 1 of 2019					    Made in: week 1 of 2019
  Basic Display Parameters & Features:				  Basic Display Parameters & Features:
    Digital display						    Digital display
    Maximum image size: 80 cm x 34 cm				    Maximum image size: 80 cm x 34 cm
    Gamma: 2.20							    Gamma: 2.20
    DPMS levels: Standby Suspend Off				    DPMS levels: Standby Suspend Off
    RGB color display						    RGB color display
    First detailed timing is the preferred timing		    First detailed timing is the preferred timing
  Color Characteristics:					  Color Characteristics:
    Red  : 0.6513, 0.3320					    Red  : 0.6513, 0.3320
    Green: 0.3066, 0.6308					    Green: 0.3066, 0.6308
    Blue : 0.1503, 0.0595					    Blue : 0.1503, 0.0595
    White: 0.3134, 0.3291					    White: 0.3134, 0.3291
  Established Timings I & II:					  Established Timings I & II:
    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz 	    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz
    DMT 0x06:   640x480    75.000000 Hz   4:3     37.500 kHz 	    DMT 0x06:   640x480    75.000000 Hz   4:3     37.500 kHz
    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz 	    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz
    DMT 0x0b:   800x600    75.000000 Hz   4:3     46.875 kHz 	    DMT 0x0b:   800x600    75.000000 Hz   4:3     46.875 kHz
    Apple   :   832x624    74.551266 Hz   4:3     49.726 kHz 	    Apple   :   832x624    74.551266 Hz   4:3     49.726 kHz
    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz 	    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz
    DMT 0x12:  1024x768    75.028582 Hz   4:3     60.023 kHz 	    DMT 0x12:  1024x768    75.028582 Hz   4:3     60.023 kHz
    DMT 0x24:  1280x1024   75.024675 Hz   5:4     79.976 kHz 	    DMT 0x24:  1280x1024   75.024675 Hz   5:4     79.976 kHz
    Apple   :  1152x870    75.061550 Hz 192:145   68.681 kHz 	    Apple   :  1152x870    75.061550 Hz 192:145   68.681 kHz
  Standard Timings:						  Standard Timings:
    GTF     :  1152x864    60.000000 Hz   4:3     53.700 kHz 	    GTF     :  1152x864    60.000000 Hz   4:3     53.700 kHz
    DMT 0x23:  1280x1024   60.019740 Hz   5:4     63.981 kHz 	    DMT 0x23:  1280x1024   60.019740 Hz   5:4     63.981 kHz
    DMT 0x55:  1280x720    60.000000 Hz  16:9     45.000 kHz 	    DMT 0x55:  1280x720    60.000000 Hz  16:9     45.000 kHz
    DMT 0x53:  1600x900    60.000000 Hz  16:9     60.000 kHz 	    DMT 0x53:  1600x900    60.000000 Hz  16:9     60.000 kHz
    DMT 0x3a:  1680x1050   59.954250 Hz  16:10    65.290 kHz 	    DMT 0x3a:  1680x1050   59.954250 Hz  16:10    65.290 kHz
    DMT 0x52:  1920x1080   60.000000 Hz  16:9     67.500 kHz 	    DMT 0x52:  1920x1080   60.000000 Hz  16:9     67.500 kHz
    DMT 0x1c:  1280x800    59.810326 Hz  16:10    49.702 kHz 	    DMT 0x1c:  1280x800    59.810326 Hz  16:10    49.702 kHz
    GTF     :  1920x1080   75.000068 Hz  16:9     84.600 kHz 	    GTF     :  1920x1080   75.000068 Hz  16:9     84.600 kHz
  Detailed Timing Descriptors:					  Detailed Timing Descriptors:
    DTD 1:  2560x1080   59.978424 Hz  64:27    66.636 kHz    	    DTD 1:  2560x1080   59.978424 Hz  64:27    66.636 kHz
                 Hfront   48 Hsync  32 Hback   80 Hpol P	                 Hfront   48 Hsync  32 Hback   80 Hpol P
                 Vfront    3 Vsync  10 Vback   18 Vpol N	                 Vfront    3 Vsync  10 Vback   18 Vpol N
    DTD 2:  1920x1080   59.991919 Hz  16:9     67.491 kHz    	    DTD 2:  1920x1080   59.991919 Hz  16:9     67.491 kHz
                 Hfront   88 Hsync  44 Hback  148 Hpol P	                 Hfront   88 Hsync  44 Hback  148 Hpol P
                 Vfront    4 Vsync   5 Vback   36 Vpol P	                 Vfront    4 Vsync   5 Vback   36 Vpol P
    Display Range Limits:					    Display Range Limits:
      Monitor ranges (GTF): 40-75 Hz V, 90-90 kHz H, max dotc	      Monitor ranges (GTF): 40-75 Hz V, 90-90 kHz H, max dotc
    Display Product Name: 'LG ULTRAWIDE'			    Display Product Name: 'LG ULTRAWIDE'
  Extension blocks: 1						  Extension blocks: 1
Checksum: 0x9a							Checksum: 0x9a

----------------						----------------

Block 1, CTA-861 Extension Block:				Block 1, CTA-861 Extension Block:
  Revision: 3							  Revision: 3
  Underscans IT Video Formats by default			  Underscans IT Video Formats by default
  Basic audio support						  Basic audio support
  Supports YCbCr 4:4:4						  Supports YCbCr 4:4:4
  Supports YCbCr 4:2:2						  Supports YCbCr 4:2:2
  Native detailed modes: 1					  Native detailed modes: 1
  Audio Data Block:						  Audio Data Block:
    Linear PCM:							    Linear PCM:
      Max channels: 2						      Max channels: 2
      Supported sample rates (kHz): 48 44.1 32			      Supported sample rates (kHz): 48 44.1 32
      Supported sample sizes (bits): 24 20 16			      Supported sample sizes (bits): 24 20 16
  Video Data Block:						  Video Data Block:
    VIC  16:  1920x1080   60.000000 Hz  16:9     67.500 kHz  	    VIC  16:  1920x1080   60.000000 Hz  16:9     67.500 kHz
    VIC   4:  1280x720    60.000000 Hz  16:9     45.000 kHz  	    VIC   4:  1280x720    60.000000 Hz  16:9     45.000 kHz
    VIC   3:   720x480    59.940060 Hz  16:9     31.469 kHz  	    VIC   3:   720x480    59.940060 Hz  16:9     31.469 kHz
    VIC   1:   640x480    59.940476 Hz   4:3     31.469 kHz  	    VIC   1:   640x480    59.940476 Hz   4:3     31.469 kHz
    VIC  31:  1920x1080   50.000000 Hz  16:9     56.250 kHz  	    VIC  31:  1920x1080   50.000000 Hz  16:9     56.250 kHz
    VIC  19:  1280x720    50.000000 Hz  16:9     37.500 kHz  	    VIC  19:  1280x720    50.000000 Hz  16:9     37.500 kHz
    VIC  18:   720x576    50.000000 Hz  16:9     31.250 kHz  	    VIC  18:   720x576    50.000000 Hz  16:9     31.250 kHz
  Speaker Allocation Data Block:				  Speaker Allocation Data Block:
    FL/FR - Front Left/Right					    FL/FR - Front Left/Right
  Vendor-Specific Data Block (HDMI), OUI 00-0C-03:		  Vendor-Specific Data Block (HDMI), OUI 00-0C-03:
    Source physical address: 2.0.0.0			      |	    Source physical address: 1.0.0.0
  Vendor-Specific Data Block (AMD), OUI 00-00-1A:		  Vendor-Specific Data Block (AMD), OUI 00-00-1A:
    Version: 1							    Version: 1
    Feature Caps: 0x01						    Feature Caps: 0x01
    Minimum Refresh Rate: 40 Hz					    Minimum Refresh Rate: 40 Hz
    Maximum Refresh Rate: 75 Hz					    Maximum Refresh Rate: 75 Hz
    Flags 1.x: 0x00						    Flags 1.x: 0x00
  Detailed Timing Descriptors:					  Detailed Timing Descriptors:
    DTD 3:   720x480    59.940060 Hz   3:2     31.469 kHz    	    DTD 3:   720x480    59.940060 Hz   3:2     31.469 kHz
                 Hfront   16 Hsync  62 Hback   60 Hpol N	                 Hfront   16 Hsync  62 Hback   60 Hpol N
                 Vfront    9 Vsync   6 Vback   30 Vpol N	                 Vfront    9 Vsync   6 Vback   30 Vpol N
    DTD 4:  2560x1080   74.991458 Hz  64:27    83.915 kHz    	    DTD 4:  2560x1080   74.991458 Hz  64:27    83.915 kHz
                 Hfront   48 Hsync  32 Hback   80 Hpol P	                 Hfront   48 Hsync  32 Hback   80 Hpol P
                 Vfront    3 Vsync  10 Vback   26 Vpol N	                 Vfront    3 Vsync  10 Vback   26 Vpol N
Checksum: 0x93  Unused space in Extension Block: 56 bytes     |	Checksum: 0xa3  Unused space in Extension Block: 56 bytes

Force-loading that EDID via the kernel command line options has no effect.

In all of these cases, when I attempt to force the resolution via new modes in xrandr, the common error I get in /var/log/Xorg.log is the following:

[ ] (II) modeset(0): Allocate new frame buffer 2560x1080 stride
[ ] (EE) modeset(0): failed to set mode: No such file or directory
[ ] (II) modeset(0): EDID vendor "GSM", prod id 30457

First line is trying to apply the newly added mode. Third line is Xorg re-probing the DDC for resolutions and falling back to a default.

I’m struggling for new avenues to explore here.

Maybe interesting info?

I had run across that as well in my searches, but it sort of dead-ends there. The card still functions within Windows driving the correct resolutions, so it’s not a limitation of the card (unless Windows is somehow forcing the A750 to speak non-standard resolutions over HDMI).

The best I can gather at this point is it is some issue with the i915 driver (I don’t have any better luck with the dev line xe). Is that probably my best bet? Reach out with some bug report to the i915 dev chain?

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I suppose you ran across this also?

I wonder if the issue is similar to this with Arc 380.

https://bbs.archlinux.org/viewtopic.php?id=294371

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Well shoot; I hadn’t come across that article yet.

Going to the bug report on freedesktop:

I have a 2560x1080@75 (LG Ultrawide) monitor and an A770, but it recognizes at most 1920x1080@60.

…that’s rather literally my problem just with the A750.

I’ll dig in over there and see what else I can find. Thank you kindly @ricklinux.

Ultimately I was able to (for now) resolve the resolution issue with the patch submitted to intel-gfx from the freedesktop bug report listed in that Arch forum link you posted.

Pulled source; applied the five patches; built; installed; rebooted into new kernel and voila full range of display modes available once again, no mucking around with EDIDs or anything!

Thank you again for your sleuthing!

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Glad i could help. I’m not that knowledgeable with all things linux or Ach but i try my best to point others in the right direction. Or at least what i think may.

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