busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Thu Jul 29, 2021 2:10 pm

I've been trying out the full KMS video driver with a large screen monitor, and found that the KMS video cases a blank screen (and "No Signal" message) when I start the desktop, but the fake KMS (fkms) driver does not.

I have
Raspberry Pi 4B 2GB, v1.1
Iiyama 3400x1440 ultra-wide display
64-bit Raspberry Pi OS (with all updates to July 28)
Kernel 5.10.17-v8+ #1421
Official Raspberry Pi power supply

My Pi is configured to boot to the command line, and I start the desktop environment by typing "startx" at the command prompt.

If /boot/config.txt contains this then I get the black screen/No Signal

Code: Select all

# The full KMS V3D driver with the built in audio driver turned off
dtoverlay=vc4-kms-v3d,noaudio
# Enable higher resolution and refresh
hdmi_enable_4kp60=1

If /boot/config.txt contains this, then the desktop loads correctly at the maximum resolution of the screen, 75Hz refresh rate.

Code: Select all

# Enable DRM VC4 V3D driver on top of the dispmanx display stack
#dtoverlay=vc4-fkms-v3d
# Enables higher resolution and refresh
hdmi_enable_4kp60=1

I used

Code: Select all

sudo rpi-update
to try the bleeding-edge (Kernel 5.10.52-v8+ #1440 plus firmware files), and saw no change in behaviour for fkms or kms.

During the black screen I can SSH to the pi with no problem. I didn't see anything interesting logged in dmesg or with journalctl -xe. If there's any other helpful place that I could look then let me know.
Last edited by busywait on Fri Jul 30, 2021 8:51 am, edited 1 time in total.


aBUGSworstnightmare
Posts: 3498
Joined: Tue Jun 30, 2015 1:35 pm

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Thu Jul 29, 2021 3:41 pm

What does 'tvservice -s' and 'tvservice -m DMT' report when you connect via SSH? And then try 'xrandr --output HDMI-1 --preferred' and let us have your feedback.
Please do this on 32-bit and 64-bit OS to figure out if this is maybe an issue only on 64-bit OS

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Thu Jul 29, 2021 9:03 pm

Still with the kernel from yesterday's rpi-update (which is the same as the latest released kernel via apt upgrade now):
Linux rpi-game 5.10.52-v8+ #1440 SMP PREEMPT Tue Jul 27 09:56:40 BST 2021 aarch64 GNU/Linux

With this in /boot/config

Code: Select all

dtoverlay=vc4-fkms-v3d
hdmi_enable_4kp60=1
I get

Code: Select all

pi@rpi-game:~ $ tvservice -s
state 0xa [HDMI CUSTOM RGB full unknown AR], 3440x1440 @ 75.00Hz, progressive
pi@rpi-game:~ $ tvservice -m DMT
Group DMT has 18 modes:
           mode 4: 640x480 @ 60Hz 4:3, clock:25MHz progressive
           mode 5: 640x480 @ 72Hz 4:3, clock:31MHz progressive
           mode 6: 640x480 @ 75Hz 4:3, clock:31MHz progressive
           mode 8: 800x600 @ 56Hz 4:3, clock:36MHz progressive
           mode 9: 800x600 @ 60Hz 4:3, clock:40MHz progressive
           mode 10: 800x600 @ 72Hz 4:3, clock:50MHz progressive
           mode 11: 800x600 @ 75Hz 4:3, clock:49MHz progressive
           mode 16: 1024x768 @ 60Hz 4:3, clock:65MHz progressive
           mode 17: 1024x768 @ 70Hz 4:3, clock:75MHz progressive
           mode 18: 1024x768 @ 75Hz 4:3, clock:78MHz progressive
           mode 28: 1280x800 @ 60Hz 16:10, clock:83MHz progressive
           mode 35: 1280x1024 @ 60Hz 5:4, clock:108MHz progressive
           mode 36: 1280x1024 @ 75Hz 5:4, clock:135MHz progressive
           mode 51: 1600x1200 @ 60Hz 4:3, clock:162MHz progressive
           mode 69: 1920x1200 @ 60Hz 16:10, clock:193MHz progressive
           mode 82: 1920x1080 @ 60Hz 16:9, clock:148MHz progressive
           mode 83: 1600x900 @ 60Hz 16:9, clock:108MHz progressive
           mode 84: 2048x1152 @ 60Hz 16:9, clock:162MHz progressive
pi@rpi-game:~ $ xrandr --output HDMI-1 --preferred
Can't open display
(The monitor is a 3440x1440 resolution display, and the desktop will start in that mode).


With this is /boot/config.txt

Code: Select all

dtoverlay=vc4-kms-v3d,noaudio
hdmi_enable_4kp60=1
I get

Code: Select all

pi@rpi-game:~ $ tvservice -s
state 0x120001 [TV is off]
pi@rpi-game:~ $ tvservice -m DMT
Group DMT has 0 modes:
pi@rpi-game:~ $ xrandr --output HDMI-1 --preferred
Can't open display

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Thu Jul 29, 2021 9:49 pm

Behaviour and command output in the 32-bit Rasberry Pi OS are the same.

aBUGSworstnightmare
Posts: 3498
Joined: Tue Jun 30, 2015 1:35 pm

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 5:16 am

Is this a monitor or TV?
What gives

Code: Select all

 tvservice -m CEA  
why do you use the parameter 'no_audio' for KMS? If this is omitted will it change anything?

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 6:59 am

aBUGSworstnightmare wrote:
Fri Jul 30, 2021 5:16 am
why do you use the parameter 'no_audio' for KMS? If this is omitted will it change anything?
Because without that parameter another audio driver is enabled and the Raspberry Pi OS (and RetroPie) audio configuration tools don't know how to use it, and I don't want to do the manual configuration to set it up.

The behaviour is the same without it (checked on 32-bit Raspberry Pi OS), for example the output from the tvservice -m DMT command that you suggested shows no modes.

Code: Select all

pi@rpi-game:~ $ uname -a
Linux rpi-game 5.10.52-v7l+ #1440 SMP Tue Jul 27 09:55:21 BST 2021 armv7l GNU/Linux

pi@rpi-game:~ $ tail /boot/config.txt
[pi4]
dtoverlay=vc4-kms-v3d
#hdmi_enable_4kp60=1
max_framebuffers=2
[all]
#dtoverlay=vc4-fkms-v3d

pi@rpi-game:~ $ tvservice -s
state 0x120001 [TV is off]

pi@rpi-game:~ $ tvservice -m DMT
Group DMT has 0 modes:

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 7:04 am

aBUGSworstnightmare wrote:
Fri Jul 30, 2021 5:16 am
Is this a monitor or TV?
What gives

Code: Select all

 tvservice -m CEA  
It's an Iiyama ProLite XUB3493WQSU monitor.

Code: Select all

pi@rpi-game:~ $ tvservice -m CEA
Group CEA has 0 modes:
(If I go back to the fake KMS (fkms) driver then I do see some TV modes offered)

aBUGSworstnightmare
Posts: 3498
Joined: Tue Jun 30, 2015 1:35 pm

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 8:00 am

Well, sorry, but I need to say that I don't understand atm how the firmware can pick up below mode when EDID has no entry for it.

Code: Select all

 pi@rpi-game:~ $ tvservice -s
state 0xa [HDMI CUSTOM RGB full unknown AR], 3440x1440 @ 75.00Hz, progressive
what gives 'xrandr --verbose'?

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 8:41 am

aBUGSworstnightmare wrote:
Fri Jul 30, 2021 8:00 am
Well, sorry, but I need to say that I don't understand atm how the firmware can pick up below mode when EDID has no entry for it.

Code: Select all

 pi@rpi-game:~ $ tvservice -s
state 0xa [HDMI CUSTOM RGB full unknown AR], 3440x1440 @ 75.00Hz, progressive
That's maybe more related to this behaviour that I'm seeing:
Desktop resolution keeps resetting [with hdmi_enable_4kp60=1 in /boot/config.txt]
aBUGSworstnightmare wrote:
Fri Jul 30, 2021 8:00 am
what gives 'xrandr --verbose'?
From SSH it always gives "Can't open display".

Inside X, with the fkms kernel I get

Code: Select all

pi@rpi-game:~ $ uname -a
Linux rpi-game 5.10.52-v8+ #1440 SMP PREEMPT Tue Jul 27 09:56:40 BST 2021 aarch64 GNU/Linux

pi@rpi-game:~ $ tail /boot/config.txt 
dtoverlay=vc4-fkms-v3d
# Increase core clock from 500MHz to 550MHz to enable higher screen res options
hdmi_enable_4kp60=1
max_framebuffers=2
arm_64bit=1

pi@rpi-game:~ $ xrandr --verbose
Screen 0: minimum 320 x 200, current 3440 x 1440, maximum 7680 x 7680
HDMI-1 connected primary 3440x1440+0+0 (0x42) normal (normal left inverted right x axis y axis) 800mm x 345mm
	Identifier: 0x40
	Timestamp:  21866
	Subpixel:   unknown
	Gamma:      1.0:1.0:1.0
	Brightness: 1.0
	Clones:    
	CRTC:       0
	CRTCs:      0
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter: 
	EDID: 
		00ffffffffffff0026cd127601010101
		021e0103805023782a8195a355539f25
		0a5054bfef80d1c0e1c0d100d1cfa940
		a9c0818081004eab70b8d1a042509060
		640820593100001a000000ff00313137
		31343030323030313231000000fd0030
		4c0f723c000a202020202020000000fc
		00504c3334393357510a2020202001f1
		020343f04f101f041303120211051407
		160615012309070783010000e200ea67
		030c002000183c67d85dc40178800068
		1a00000101304bede305e000e6060701
		8b6011e77c70a0d0a0295030203a0020
		593100001a565e00a0a0a02950302035
		0020593100001a9855b8dc60a0425048
		30640820593100001a0000000000008d
	Broadcast RGB: Automatic 
		supported: Automatic, Full, Limited 16:235
	bottom margin: 0 
		range: (0, 100)
	top margin: 0 
		range: (0, 100)
	right margin: 0 
		range: (0, 100)
	left margin: 0 
		range: (0, 100)
	link-status: Good 
		supported: Good, Bad
	CONNECTOR_ID: 89 
		supported: 89
	non-desktop: 0 
		range: (0, 1)
  3440x1440 (0x42) 438.540MHz +HSync -VSync *current +preferred
        h: width  3440 start 3584 end 3680 total 3880 skew    0 clock 113.03KHz
        v: height 1440 start 1478 end 1482 total 1506           clock  75.05Hz
  3440x1440 (0x43) 319.750MHz +HSync -VSync
        h: width  3440 start 3488 end 3520 total 3600 skew    0 clock  88.82KHz
        v: height 1440 start 1443 end 1453 total 1481           clock  59.97Hz
  2560x1440 (0x44) 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
  1720x1440 (0x45) 219.120MHz +HSync -VSync
        h: width  1720 start 1792 end 1840 total 1940 skew    0 clock 112.95KHz
        v: height 1440 start 1478 end 1482 total 1506           clock  75.00Hz
  2048x1152 (0x46) 162.000MHz +HSync +VSync
        h: width  2048 start 2074 end 2154 total 2250 skew    0 clock  72.00KHz
        v: height 1152 start 1153 end 1156 total 1200           clock  60.00Hz
  1920x1200 (0x47) 154.000MHz +HSync -VSync
        h: width  1920 start 1968 end 2000 total 2080 skew    0 clock  74.04KHz
        v: height 1200 start 1203 end 1209 total 1235           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) 148.500MHz +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 (0x4a) 148.500MHz +HSync +VSync
        h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  56.25KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  50.00Hz
  1920x1080 (0x4b) 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
  1920x1080i (0x4c) 74.250MHz +HSync +VSync Interlace
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  33.75KHz
        v: height 1080 start 1084 end 1094 total 1125           clock  60.00Hz
  1920x1080i (0x4d) 74.250MHz +HSync +VSync Interlace
        h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  28.12KHz
        v: height 1080 start 1084 end 1094 total 1125           clock  50.00Hz
  1920x1080i (0x4e) 74.176MHz +HSync +VSync Interlace
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  33.72KHz
        v: height 1080 start 1084 end 1094 total 1125           clock  59.94Hz
  1600x1200 (0x4f) 162.000MHz +HSync +VSync
        h: width  1600 start 1664 end 1856 total 2160 skew    0 clock  75.00KHz
        v: height 1200 start 1201 end 1204 total 1250           clock  60.00Hz
  1600x900 (0x50) 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 (0x51) 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 (0x52) 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
  1280x800 (0x53) 71.000MHz +HSync -VSync
        h: width  1280 start 1328 end 1360 total 1440 skew    0 clock  49.31KHz
        v: height  800 start  803 end  809 total  823           clock  59.91Hz
  1152x864 (0x54) 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 (0x55) 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 (0x56) 74.250MHz +HSync +VSync
        h: width  1280 start 1720 end 1760 total 1980 skew    0 clock  37.50KHz
        v: height  720 start  725 end  730 total  750           clock  50.00Hz
  1280x720 (0x57) 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 (0x58) 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 (0x59) 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 (0x5a) 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 (0x5b) 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 (0x5c) 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 (0x5d) 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 (0x5e) 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 (0x5f) 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
  720x576 (0x60) 27.000MHz -HSync -VSync
        h: width   720 start  732 end  796 total  864 skew    0 clock  31.25KHz
        v: height  576 start  581 end  586 total  625           clock  50.00Hz
  720x576i (0x61) 13.500MHz -HSync -VSync Interlace
        h: width   720 start  732 end  795 total  864 skew    0 clock  15.62KHz
        v: height  576 start  580 end  586 total  625           clock  50.00Hz
  720x480 (0x62) 27.027MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.50KHz
        v: height  480 start  489 end  495 total  525           clock  60.00Hz
  720x480 (0x63) 27.000MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.47KHz
        v: height  480 start  489 end  495 total  525           clock  59.94Hz
  720x480i (0x64) 13.514MHz -HSync -VSync Interlace
        h: width   720 start  739 end  801 total  858 skew    0 clock  15.75KHz
        v: height  480 start  488 end  494 total  525           clock  60.00Hz
  720x480i (0x65) 13.500MHz -HSync -VSync Interlace
        h: width   720 start  739 end  801 total  858 skew    0 clock  15.73KHz
        v: height  480 start  488 end  494 total  525           clock  59.94Hz
  640x480 (0x66) 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 (0x67) 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 (0x68) 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 (0x69) 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 (0x6a) 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 (0x6b) 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
pi@rpi-game:~ $ 

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 8:53 am

I think that this might be independent of screen resolution - I plugged the pi into my TV (1080p) and got the same blank screen/no signal behaviour when I start the desktop (startx command).

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 29357
Joined: Sat Jul 30, 2011 7:41 pm

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 9:46 am

Have you tried the other HDMI port?
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Working in the Applications Team.

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5805
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 10:06 am

Two things.
tvservice uses the custom firmware interface to query display. The kms driver doesn't use the firmware for display.
tvservice will never provide useful information. You need to use standard linux tools for this. modetest is one option.

Second, you can't run x commands over ssh without specifying the display to use.
Either enter the command on an actual terminal visible on the display, or specify the display explicitly. e.g.

Code: Select all

DISPLAY=:0 xrandr

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 10:58 am

jamesh wrote:
Fri Jul 30, 2021 9:46 am
Have you tried the other HDMI port?
I had not tried that. So...

I booted with kms, started the desktop, and then moved the HDMI cable to the other output (furthest from the power input). No desktop appeared.

I rebooted the machine with the HDMI cable in the output furthest from the power input. The machine boots to a command line, but I saw only a black screen. I moved the HDMI cable back to the output close to the power input and the console appeared.

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 11:13 am

dom wrote:
Fri Jul 30, 2021 10:06 am
tvservice uses the custom firmware interface to query display. The kms driver doesn't use the firmware for display.
tvservice will never provide useful information. You need to use standard linux tools for this. modetest is one option.
modetest is not in the buster apt repositories. Let me know how to get it if it would be super helpful.
dom wrote:
Fri Jul 30, 2021 10:06 am
Second, you can't run x commands over ssh without specifying the display to use.
Either enter the command on an actual terminal visible on the display, or specify the display explicitly. e.g.

Code: Select all

DISPLAY=:0 xrandr
I booted to a console with the full kms driver
started X, saw a black screen
logged in over ssh, ran DISPLAY=:0 xrandr --verbose

Code: Select all

Linux rpi-game 5.10.52-v8+ #1440 SMP PREEMPT Tue Jul 27 09:56:40 BST 2021 aarch64
pi@rpi-game:~ $ DISPLAY=:0 xrandr --verbose
Screen 0: minimum 320 x 200, current 3440 x 1440, maximum 7680 x 7680
HDMI-1 connected primary 3440x1440+0+0 (0x48) normal (normal left inverted right x axis y axis) 800mm x 345mm
        Identifier: 0x45
        Timestamp:  488931
        Subpixel:   unknown
        Gamma:      1.0:1.0:1.0
        Brightness: 1.0
        Clones:
        CRTC:       0
        CRTCs:      0
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        EDID:
                00ffffffffffff0026cd127601010101
                021e0103805023782a8195a355539f25
                0a5054bfef80d1c0e1c0d100d1cfa940
                a9c0818081004eab70b8d1a042509060
                640820593100001a000000ff00313137
                31343030323030313231000000fd0030
                4c0f723c000a202020202020000000fc
                00504c3334393357510a2020202001f1
                020343f04f101f041303120211051407
                160615012309070783010000e200ea67
                030c002000183c67d85dc40178800068
                1a00000101304bede305e000e6060701
                8b6011e77c70a0d0a0295030203a0020
                593100001a565e00a0a0a02950302035
                0020593100001a9855b8dc60a0425048
                30640820593100001a0000000000008d
        max bpc: 8
                range: (8, 12)
        bottom margin: 0
                range: (0, 100)
        top margin: 0
                range: (0, 100)
        right margin: 0
                range: (0, 100)
        left margin: 0
                range: (0, 100)
        Colorspace: Default
                supported: Default, SMPTE_170M_YCC, BT709_YCC, XVYCC_601, XVYCC_709, SYCC_601, opYCC_601, opRGB, BT2020_CYCC, BT2020_RGB, BT2020_YCC, DCI-P3_RGB_D65, DCI-P3_RGB_Theater
        link-status: Good
                supported: Good, Bad
        CONNECTOR_ID: 32
                supported: 32
        non-desktop: 0
                range: (0, 1)
  3440x1440 (0x48) 319.750MHz +HSync -VSync *current
        h: width  3440 start 3488 end 3520 total 3600 skew    0 clock  88.82KHz
        v: height 1440 start 1443 end 1453 total 1481           clock  59.97Hz
  2560x1440 (0x49) 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
  1720x1440 (0x4a) 219.120MHz +HSync -VSync
        h: width  1720 start 1792 end 1840 total 1940 skew    0 clock 112.95KHz
        v: height 1440 start 1478 end 1482 total 1506           clock  75.00Hz
  2048x1152 (0x4b) 162.000MHz +HSync +VSync
        h: width  2048 start 2074 end 2154 total 2250 skew    0 clock  72.00KHz
        v: height 1152 start 1153 end 1156 total 1200           clock  60.00Hz
  1920x1200 (0x4c) 154.000MHz +HSync -VSync
        h: width  1920 start 1968 end 2000 total 2080 skew    0 clock  74.04KHz
        v: height 1200 start 1203 end 1209 total 1235           clock  59.95Hz
  1920x1080 (0x4d) 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 (0x4e) 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 (0x4f) 148.500MHz +HSync +VSync
        h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  56.25KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  50.00Hz
  1920x1080 (0x50) 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
  1920x1080i (0x51) 74.250MHz +HSync +VSync Interlace
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  33.75KHz
        v: height 1080 start 1084 end 1094 total 1125           clock  60.00Hz
  1920x1080i (0x52) 74.250MHz +HSync +VSync Interlace
        h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  28.12KHz
        v: height 1080 start 1084 end 1094 total 1125           clock  50.00Hz
  1920x1080i (0x53) 74.176MHz +HSync +VSync Interlace
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  33.72KHz
        v: height 1080 start 1084 end 1094 total 1125           clock  59.94Hz
  1600x1200 (0x54) 162.000MHz +HSync +VSync
        h: width  1600 start 1664 end 1856 total 2160 skew    0 clock  75.00KHz
        v: height 1200 start 1201 end 1204 total 1250           clock  60.00Hz
  1600x900 (0x55) 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 (0x56) 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 (0x57) 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
  1280x800 (0x58) 71.000MHz +HSync -VSync
        h: width  1280 start 1328 end 1360 total 1440 skew    0 clock  49.31KHz
        v: height  800 start  803 end  809 total  823           clock  59.91Hz
  1152x864 (0x59) 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 (0x5a) 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 (0x5b) 74.250MHz +HSync +VSync
        h: width  1280 start 1720 end 1760 total 1980 skew    0 clock  37.50KHz
        v: height  720 start  725 end  730 total  750           clock  50.00Hz
  1280x720 (0x5c) 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 (0x5d) 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 (0x5e) 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 (0x5f) 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 (0x60) 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 (0x61) 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 (0x62) 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 (0x63) 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 (0x64) 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
  720x576 (0x65) 27.000MHz -HSync -VSync
        h: width   720 start  732 end  796 total  864 skew    0 clock  31.25KHz
        v: height  576 start  581 end  586 total  625           clock  50.00Hz
  720x576i (0x66) 13.500MHz -HSync -VSync Interlace
        h: width   720 start  732 end  795 total  864 skew    0 clock  15.62KHz
        v: height  576 start  580 end  586 total  625           clock  50.00Hz
  720x480 (0x67) 27.027MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.50KHz
        v: height  480 start  489 end  495 total  525           clock  60.00Hz
  720x480 (0x68) 27.000MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.47KHz
        v: height  480 start  489 end  495 total  525           clock  59.94Hz
  720x480i (0x69) 13.514MHz -HSync -VSync Interlace
        h: width   720 start  739 end  801 total  858 skew    0 clock  15.75KHz
        v: height  480 start  488 end  494 total  525           clock  60.00Hz
  720x480i (0x6a) 13.500MHz -HSync -VSync Interlace
        h: width   720 start  739 end  801 total  858 skew    0 clock  15.73KHz
        v: height  480 start  488 end  494 total  525           clock  59.94Hz
  640x480 (0x6b) 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 (0x6c) 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 (0x6d) 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 (0x6e) 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 (0x6f) 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 (0x70) 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
HDMI-2 disconnected (normal left inverted right x axis y axis)
        Identifier: 0x46
        Timestamp:  488931
        Subpixel:   unknown
        Clones:
        CRTCs:      4
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        max bpc: 8
                range: (8, 12)
        bottom margin: 0
                range: (0, 100)
        top margin: 0
                range: (0, 100)
        right margin: 0
                range: (0, 100)
        left margin: 0
                range: (0, 100)
        Colorspace: Default
                supported: Default, SMPTE_170M_YCC, BT709_YCC, XVYCC_601, XVYCC_709, SYCC_601, opYCC_601, opRGB, BT2020_CYCC, BT2020_RGB, BT2020_YCC, DCI-P3_RGB_D65, DCI-P3_RGB_Theater
        link-status: Good
                supported: Good, Bad
        CONNECTOR_ID: 40
                supported: 40
        non-desktop: 0
                range: (0, 1)
Ran DISPLAY=:0 xrandr --output HDMI-1 --preferred and the desktop appeared!

Ran DISPLAY=:0 xrandr --verbose again

Code: Select all

pi@rpi-game:~ $ DISPLAY=:0 xrandr --verbose
Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 7680 x 7680
HDMI-1 connected primary 1920x1200+0+0 (0x4c) normal (normal left inverted right x axis y axis) 800mm x 345mm
        Identifier: 0x45
        Timestamp:  655955
        Subpixel:   unknown
        Gamma:      1.0:1.0:1.0
        Brightness: 1.0
        Clones:
        CRTC:       0
        CRTCs:      0
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        EDID:
                00ffffffffffff0026cd127601010101
                021e0103805023782a8195a355539f25
                0a5054bfef80d1c0e1c0d100d1cfa940
                a9c0818081004eab70b8d1a042509060
                640820593100001a000000ff00313137
                31343030323030313231000000fd0030
                4c0f723c000a202020202020000000fc
                00504c3334393357510a2020202001f1
                020343f04f101f041303120211051407
                160615012309070783010000e200ea67
                030c002000183c67d85dc40178800068
                1a00000101304bede305e000e6060701
                8b6011e77c70a0d0a0295030203a0020
                593100001a565e00a0a0a02950302035
                0020593100001a9855b8dc60a0425048
                30640820593100001a0000000000008d
        max bpc: 8
                range: (8, 12)
        bottom margin: 0
                range: (0, 100)
        top margin: 0
                range: (0, 100)
        right margin: 0
                range: (0, 100)
        left margin: 0
                range: (0, 100)
        Colorspace: Default
                supported: Default, SMPTE_170M_YCC, BT709_YCC, XVYCC_601, XVYCC_709, SYCC_601, opYCC_601, opRGB, BT2020_CYCC, BT2020_RGB, BT2020_YCC, DCI-P3_RGB_D65, DCI-P3_RGB_Theater
        link-status: Good
                supported: Good, Bad
        CONNECTOR_ID: 32
                supported: 32
        non-desktop: 0
                range: (0, 1)
  3440x1440 (0x48) 319.750MHz +HSync -VSync
        h: width  3440 start 3488 end 3520 total 3600 skew    0 clock  88.82KHz
        v: height 1440 start 1443 end 1453 total 1481           clock  59.97Hz
  2560x1440 (0x49) 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
  1720x1440 (0x4a) 219.120MHz +HSync -VSync
        h: width  1720 start 1792 end 1840 total 1940 skew    0 clock 112.95KHz
        v: height 1440 start 1478 end 1482 total 1506           clock  75.00Hz
  2048x1152 (0x4b) 162.000MHz +HSync +VSync
        h: width  2048 start 2074 end 2154 total 2250 skew    0 clock  72.00KHz
        v: height 1152 start 1153 end 1156 total 1200           clock  60.00Hz
  1920x1200 (0x4c) 154.000MHz +HSync -VSync *current
        h: width  1920 start 1968 end 2000 total 2080 skew    0 clock  74.04KHz
        v: height 1200 start 1203 end 1209 total 1235           clock  59.95Hz
  1920x1080 (0x4d) 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 (0x4e) 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 (0x4f) 148.500MHz +HSync +VSync
        h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  56.25KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  50.00Hz
  1920x1080 (0x50) 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
  1920x1080i (0x51) 74.250MHz +HSync +VSync Interlace
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  33.75KHz
        v: height 1080 start 1084 end 1094 total 1125           clock  60.00Hz
  1920x1080i (0x52) 74.250MHz +HSync +VSync Interlace
        h: width  1920 start 2448 end 2492 total 2640 skew    0 clock  28.12KHz
        v: height 1080 start 1084 end 1094 total 1125           clock  50.00Hz
  1920x1080i (0x53) 74.176MHz +HSync +VSync Interlace
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  33.72KHz
        v: height 1080 start 1084 end 1094 total 1125           clock  59.94Hz
  1600x1200 (0x54) 162.000MHz +HSync +VSync
        h: width  1600 start 1664 end 1856 total 2160 skew    0 clock  75.00KHz
        v: height 1200 start 1201 end 1204 total 1250           clock  60.00Hz
  1600x900 (0x55) 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 (0x56) 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 (0x57) 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
  1280x800 (0x58) 71.000MHz +HSync -VSync
        h: width  1280 start 1328 end 1360 total 1440 skew    0 clock  49.31KHz
        v: height  800 start  803 end  809 total  823           clock  59.91Hz
  1152x864 (0x59) 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 (0x5a) 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 (0x5b) 74.250MHz +HSync +VSync
        h: width  1280 start 1720 end 1760 total 1980 skew    0 clock  37.50KHz
        v: height  720 start  725 end  730 total  750           clock  50.00Hz
  1280x720 (0x5c) 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 (0x5d) 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 (0x5e) 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 (0x5f) 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 (0x60) 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 (0x61) 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 (0x62) 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 (0x63) 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 (0x64) 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
  720x576 (0x65) 27.000MHz -HSync -VSync
        h: width   720 start  732 end  796 total  864 skew    0 clock  31.25KHz
        v: height  576 start  581 end  586 total  625           clock  50.00Hz
  720x576i (0x66) 13.500MHz -HSync -VSync Interlace
        h: width   720 start  732 end  795 total  864 skew    0 clock  15.62KHz
        v: height  576 start  580 end  586 total  625           clock  50.00Hz
  720x480 (0x67) 27.027MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.50KHz
        v: height  480 start  489 end  495 total  525           clock  60.00Hz
  720x480 (0x68) 27.000MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.47KHz
        v: height  480 start  489 end  495 total  525           clock  59.94Hz
  720x480i (0x69) 13.514MHz -HSync -VSync Interlace
        h: width   720 start  739 end  801 total  858 skew    0 clock  15.75KHz
        v: height  480 start  488 end  494 total  525           clock  60.00Hz
  720x480i (0x6a) 13.500MHz -HSync -VSync Interlace
        h: width   720 start  739 end  801 total  858 skew    0 clock  15.73KHz
        v: height  480 start  488 end  494 total  525           clock  59.94Hz
  640x480 (0x6b) 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 (0x6c) 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 (0x6d) 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 (0x6e) 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 (0x6f) 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 (0x70) 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
HDMI-2 disconnected (normal left inverted right x axis y axis)
        Identifier: 0x46
        Timestamp:  655955
        Subpixel:   unknown
        Clones:
        CRTCs:      4
        Transform:  1.000000 0.000000 0.000000
                    0.000000 1.000000 0.000000
                    0.000000 0.000000 1.000000
                   filter:
        max bpc: 8
                range: (8, 12)
        bottom margin: 0
                range: (0, 100)
        top margin: 0
                range: (0, 100)
        right margin: 0
                range: (0, 100)
        left margin: 0
                range: (0, 100)
        Colorspace: Default
                supported: Default, SMPTE_170M_YCC, BT709_YCC, XVYCC_601, XVYCC_709, SYCC_601, opYCC_601, opRGB, BT2020_CYCC, BT2020_RGB, BT2020_YCC, DCI-P3_RGB_D65, DCI-P3_RGB_Theater
        link-status: Good
                supported: Good, Bad
        CONNECTOR_ID: 40
                supported: 40
        non-desktop: 0
                range: (0, 1)
Changes in my /boot/config.txt

Code: Select all

# Enable full KRM driver without the built in audio (use Broadcom firmware audio)
dtoverlay=vc4-kms-v3d,noaudio
# Increase core clock from 500MHz to 550MHz to enable higher screen res options
#hdmi_enable_4kp60=1
# NOOBS Auto-generated Settings:

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5805
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 11:55 am

busywait wrote:
Fri Jul 30, 2021 11:13 am
modetest is not in the buster apt repositories. Let me know how to get it if it would be super helpful.
Ah yes. It is in Bullseye, but too new for Buster.
You can compile from source here:
https://gitlab.freedesktop.org/mesa/drm ... s/modetest

kmsxx is also useful. See: https://github.com/tomba/kmsxx
kmsprint provides a concise view of display settings.

aBUGSworstnightmare
Posts: 3498
Joined: Tue Jun 30, 2015 1:35 pm

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 12:38 pm

Code: Select all

DISPLAY=:0 xrandr --verbose
but Dom beat me on this in case of running the command over SSH.

I seen a similar problem when using two displays were none of them came up after connecting HDMI0 (HDMI-1 in X). Display only started after running 'DISPLAY=:0 xrandr --output HDMI-1 --preferred'
Problem in my case was that one display resolution was smaller than the one of HDMI-1, when looking at it in screen configuration utility is was lying underneath the bigger one which caused this issue.
Moving it left or bottom solved the issue (even when only a fraction of it exceeded the horizontal resolution it was 'cloned-like; full clone never worked (as --panning doesn't work as well which might be related somehow)). Hit this problem when working on the DSI8x driver, trying to connect a HDMI display in addition. What was causing this issue - as it started with a new kernel release, but can't remember which one - is unknown to me!

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 12:44 pm

dom wrote:
Fri Jul 30, 2021 11:55 am
busywait wrote:
Fri Jul 30, 2021 11:13 am
modetest is not in the buster apt repositories
Ah yes. It is in Bullseye, but too new for Buster.
I'm guessing that if I change the word buster to bullseye in all of the .list files in /etc/apt and then run apt full-upgrade then I'll be on bullseye with all the new stuff? I've started that process. Maybe everything will just work after?

I'm only checking what works in a clean install I don't have anything to loose. I don't need to "fix" this issue, I've now got some workarounds
1/ Use the fkms kernel for the desktop
2/ Run "DISPLAY=:0 xrandr --verbose" over ssh to have the kms desktop kicked into life

Is this something that feels like a bug, or have I just stumbled in to some work in progress? I'll keep the 32-bit OS on buster for a day or so in case I've got an obscure setup.

Dom - did you also see this Desktop resolution keeps resetting with hdmi_enable_4kp60? That's quite annoying sometimes.

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 12:55 pm

aBUGSworstnightmare wrote:
Fri Jul 30, 2021 12:38 pm
but Dom beat me on this in case of running the command over SSH.
Heh, thanks for your help! I really don't know my way around any of the configs or debugging utilities - interesting.

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5805
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 1:04 pm

busywait wrote:
Fri Jul 30, 2021 12:44 pm
I'm guessing that if I change the word buster to bullseye in all of the .list files in /etc/apt and then run apt full-upgrade then I'll be on bullseye with all the new stuff? I've started that process. Maybe everything will just work after?
I wouldn't recommend that. Bullseye hasn't been officially released yet (14th August) and the raspberry pi repos haven't been updated for bullseye yet.

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 1:19 pm

dom wrote:
Fri Jul 30, 2021 1:04 pm
busywait wrote:
Fri Jul 30, 2021 12:44 pm
I'm guessing that if I change the word buster to bullseye in all of the .list files in /etc/apt and then run apt full-upgrade then I'll be on bullseye with all the new stuff? I've started that process. Maybe everything will just work after?
I wouldn't recommend that. Bullseye hasn't been officially released yet (14th August) and the raspberry pi repos haven't been updated for bullseye yet.
OK. Too late, finished. The black-screen behaviour in bullseye is similar to buster, and modetest not in the bullseye repo either yet.

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5805
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: Starting the desktop at 3440x1440 (X/Pixel) with Full KMS causes a blank screen (No Signal)

Fri Jul 30, 2021 1:24 pm

busywait wrote:
Fri Jul 30, 2021 1:19 pm
dom wrote:
Fri Jul 30, 2021 1:04 pm
busywait wrote:
Fri Jul 30, 2021 12:44 pm
I'm guessing that if I change the word buster to bullseye in all of the .list files in /etc/apt and then run apt full-upgrade then I'll be on bullseye with all the new stuff? I've started that process. Maybe everything will just work after?
I wouldn't recommend that. Bullseye hasn't been officially released yet (14th August) and the raspberry pi repos haven't been updated for bullseye yet.
OK. Too late, finished. The black-screen behaviour in bullseye is similar to buster, and modetest not in the bullseye repo either yet.
modetest is in package libdrm-tests on bullsyeye.

ammonitida
Posts: 27
Joined: Sat Dec 12, 2020 6:42 pm

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Sun Aug 01, 2021 2:32 pm

busywait wrote:
Fri Jul 30, 2021 6:59 am
aBUGSworstnightmare wrote:
Fri Jul 30, 2021 5:16 am
why do you use the parameter 'no_audio' for KMS? If this is omitted will it change anything?
Because without that parameter another audio driver is enabled and the Raspberry Pi OS (and RetroPie) audio configuration tools don't know how to use it, and I don't want to do the manual configuration to set it up.

The behaviour is the same without it (checked on 32-bit Raspberry Pi OS), for example the output from the tvservice -m DMT command that you suggested shows no modes.

Code: Select all

pi@rpi-game:~ $ uname -a
Linux rpi-game 5.10.52-v7l+ #1440 SMP Tue Jul 27 09:55:21 BST 2021 armv7l GNU/Linux

pi@rpi-game:~ $ tail /boot/config.txt
[pi4]
dtoverlay=vc4-kms-v3d
#hdmi_enable_4kp60=1
max_framebuffers=2
[all]
#dtoverlay=vc4-fkms-v3d

pi@rpi-game:~ $ tvservice -s
state 0x120001 [TV is off]

pi@rpi-game:~ $ tvservice -m DMT
Group DMT has 0 modes:
i had trouble getting sound to work with full kms, psx rearmed, and retropie. if i put in "noaudio", would that fix it?

busywait
Posts: 120
Joined: Sat May 09, 2020 10:48 pm
Location: Southampton, UK

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Mon Aug 02, 2021 7:03 am

ammonitida wrote:
Sun Aug 01, 2021 2:32 pm
i had trouble getting sound to work with full kms, psx rearmed, and retropie. if i put in "noaudio", would that fix it?
I don't know, but it's quick to try.

After, try using the retropie sound setup option in the Emulation Station menu to reset your sound configurations. If that doesn't work, open a thread over on https://retropie.org.uk/forum/

ammonitida
Posts: 27
Joined: Sat Dec 12, 2020 6:42 pm

Re: Starting the desktop at 3440x1440 (X/Pixel) with KMS causes a blank screen (No Signal)

Mon Aug 02, 2021 5:30 pm

busywait wrote:
Mon Aug 02, 2021 7:03 am
ammonitida wrote:
Sun Aug 01, 2021 2:32 pm
i had trouble getting sound to work with full kms, psx rearmed, and retropie. if i put in "noaudio", would that fix it?
I don't know, but it's quick to try.

After, try using the retropie sound setup option in the Emulation Station menu to reset your sound configurations. If that doesn't work, open a thread over on https://retropie.org.uk/forum/
problem is, the last time i tried, i bricked my OS (raspian 32-bit OS) when i attempted to go back to fkms (i just deleted the kms line and replaced it with the original). so im kind of afraid of bricking again and having to switch out sdcards (my sd card spring loader is a little finicky). i hoping you had experience since you mentioned retropie. have you used the included psx rearmed emulator on full kms yet? was the sound working or garbled? it was garbled for me but worked fine on both megadrive emulators

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