I have a jetson nano struggling to display on a particular HDMI screen. The HDMI screen functions as expected when connected to my laptop. I’ve found both my laptop and the jetson read the same EDID, and when I use xrandr I can see my laptop chooses a mode that exactly matches the EDID. However the jetson’s mode has slightly different (higher) frequencies than are given in the EDID. I assume it’s doing something like choosing from its supported modes whichever is the closest match?
I think I’ve seen from other posts people doing kernel customisation to hardcode the display edid regardless of what is read from the device - is there a way I can find the list of supported modes for experimenting with this?
What kind of difference did you see there? How did you observe it?
Using xrandr --verbose on the jetson I get:
HDMI-0 connected (normal left inverted right x axis y axis)
Identifier: 0x18c
Timestamp: 174567
Subpixel: unknown
Clones:
CRTCs: 0
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
EDID:
00ffffffffffff003354010000000000
0c1b0103800000780a07f59a564e8626
1e505400000000000000000000000000
000000000000c5644049b0a010503208
82005aa000000018000000fc00596f6e
6758696e672020202020000000ff0030
303030303030302020202020000000fd
00174b0ff022000a2020202020200140
02031774470000000000000023097f07
66030c00300080c5644049b0a0105032
0882005aa000000018c5644049b0a010
50320882005aa000000018c5644049b0
a01050320882005aa000000018c56440
49b0a01050320882005aa000000018c5
644049b0a01050320882005aa0000000
18000000000000000000000000000062
TegraOverlayBlendmode: Opaque
supported: Opaque, SourceAlphaBlend, PremultSourceAlphaBlend
TegraOverlayPriority: 255
range: (0, 255)
BorderDimensions: 4
supported: 4
Border: 0 0 0 0
range: (0, 65535)
SignalFormat: TMDS
supported: TMDS
ConnectorType: HDMI
2880x1440 (0x1aa) 257.997MHz -HSync -VSync +preferred
h: width 2880 start 2930 end 2938 total 2953 skew 0 clock 87.37KHz
v: height 1440 start 1448 end 1450 total 1456 clock 60.01Hz
640x350 (0x1ab) 31.500MHz +HSync -VSync
h: width 640 start 672 end 736 total 832 skew 0 clock 37.86KHz
v: height 350 start 382 end 385 total 445 clock 85.08Hz
On my laptop I get:
HDMI-1-0 connected 2880x1440+1920+0 (0xbca) normal (normal left inverted right x axis y axis) 90mm x 160mm
Identifier: 0x205
Timestamp: 206553584
Subpixel: unknown
Gamma: 1.0:1.0:1.0
Brightness: 1.0
Clones:
CRTC: 3
CRTCs: 3 4 5 6
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
EDID:
00ffffffffffff003354010000000000
0c1b0103800000780a07f59a564e8626
1e505400000000000000000000000000
000000000000c5644049b0a010503208
82005aa000000018000000fc00596f6e
6758696e672020202020000000ff0030
303030303030302020202020000000fd
00174b0ff022000a2020202020200140
02031774470000000000000023097f07
66030c00300080c5644049b0a0105032
0882005aa000000018c5644049b0a010
50320882005aa000000018c5644049b0
a01050320882005aa000000018c56440
49b0a01050320882005aa000000018c5
644049b0a01050320882005aa0000000
18000000000000000000000000000062
_MUTTER_PRESENTATION_OUTPUT: 0
PRIME Synchronization: supported: ?, ?
CTM: 206725805 1 684747770 -2147483648 441321830 0 169078062 -2147483648 949583784 1 770427125 -2147483648 89028996 -2147483648 613386899 -2147483648
717188301 1
CscMatrix: 68690 -10448 6734 0 -2579 80025 -11755 0 -1358 -9359 76479 0
BorderDimensions: 4
supported: 4
Border: 0 0 0 0
range: (0, 65535)
SignalFormat: TMDS
supported: TMDS
ConnectorType: HDMI
ConnectorNumber: 0
_ConnectorLocation: 0
non-desktop: 0
supported: 0, 1
2880x1440 (0xbca) 257.970MHz -HSync -VSync *current +preferred
h: width 2880 start 2930 end 2938 total 2953 skew 0 clock 87.36KHz
v: height 1440 start 1448 end 1450 total 1456 clock 60.00Hz
The laptop displays correctly, but the jetson just gives a black screen. the 640x350 mode which appears on jetson does display, but only on part of the screen and with repeats
We only suggest to run common CEA modes on Jetson Nano.
Some other modes may not support.
Is there a list of supported modes somewhere?
I would suggest you just pick up some common modes like 720p/1080p/4k@30.
Btw, you should validate the checksum of the EDID at:
http://www.edidreader.com/
Almost forgot…in “/etc/X11/xorg.conf” you can add a line to the Section "Device" and the driver will tell you what it thinks of each mode the monitor reports (in the “/var/log/Xorg.0.log”):
Section "Device"
Option "ModeDebug"
...