does your monitor has an DVI connector together with the VGA connector ? my old monitor has it,so I’ve been able to use it instead of using the VGA. and it worked. (I’ve bought the amazon basic hdmi to dvi cable) instead,you can try to follow this tutorial :
Thanks, I’ll try that. I’ve read elsewhere that EDID from a dtb is the “other” way to accept one, but was hoping to just use the default fallback one.
May end up understanding the whole process :)
ok. I prefer to understand a different kind of processes than those of the monitors :)
No joy.
Now I have the whole manager installed, and know much more of DTBs.
The instructions are for a Nano, the 2GB is a different beast but after understanding things involved I was able to flash a new DTB with embedded EDID info for (both?) devices (sor/sor1). The info gets there because you can see it in /proc/device-tree/… but the port stays “disconnected” and cat /sys/kernel/debug/tegradc.0/edid returns “No EDID”.
Sorry, got carried away with the other alternative. I had ModeDebug enabled so here is a current Xorg.log output. Not much anything that seems related to EDID though.Xorg.log (10.6 KB)
That log stops before ever reaching EDID related steps. It is as if the server crashes and does not log the crash. Are you sure that is the full log?
Yes, that’s all there is. I’m accessing the board via ssh cause I’ve no display :-/
And X is running:
5379 tty7 Ssl+ 0:01 /usr/lib/xorg/Xorg -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
root@jetson:/var/log# cat /sys/kernel/debug/tegra_hdmi/hotplug
hdmi hpd state: 0
root@jetson:/var/log# cat /sys/kernel/debug/tegradc.0/edid
No EDID
root@jetson:/var/log# export DISPLAY=:0
root@jetson:/var/log# xrandr
Screen 0: minimum 8 x 8, current 640 x 480, maximum 16384 x 16384
(shrug)
Tried yet another option, and did not work either :(
Based on Tegra Linux Driver it seems that with some monitors there is a known EDID management issue so the work around is to fix the settings via a script that touches the DTB.
The script is nv-enable-hard-coded-kernel-boot-display-mode.sh, and it writes a series of properties for fbconsole, namely:
fbcon_node=“/host1x/sor2/hdmi-display/nvidia,fbcon-default-mode”
properties=(
“clock-frequency:27027000”
“hactive:720”
“vactive:480”
“hfront-porch:16”
“hback-porch:60”
“hsync-len:62”
“vfront-porch:9”
“vback-porch:30”
“vsync-len:6”
“nvidia,h-ref-to-sync:1”
“nvidia,v-ref-to-sync:1”
“flags:0x00000003”
“vmode:0x00400000”
)
But did not work. Info is there, I can see it in the booted kernel, but hdmi shows disconnected.
I have not used this script, but if you did make a change, then you’d want to verify the change actually made its way into the device tree. If this made its way in, then you should be able to:
cd /proc/device-tree/host1x/sor2/hdmi-display
…and then explore for “nvidia,fbcon-default-mode”. From there you can verify each item.
Or you could export to source dts format:
dtc -I fs -O dts -o extracted.dts /proc/device-tree
(and then see if the tree actually has your modifications)
I have already verified it, and it’s there. In fact, if I run fbset, it shows those values.
(sor1 not sor2 because that’s the node the Nano 2G uses)
But… hdmi is down and shows disconnected.
This is so …hard to find the word. It’s driving me to places I did not want to go.
Oh well. this was all to explore edge ML, and I guess I will stay in the cloud for the time being.
It might be that there are other requirements beyond the device tree edit, but since I have not done this before I think someone from NVIDIA will need to comment. At this point you at least know the device tree installation worked.
Well, I was about to give up when I read a post related to hotplug not working and a recipe to force hdmi in connected state. After “echo 1 > /sys/kernel/debug/tegra_hdmi/hotplug” nothing seemed to happen, so I was shuting the board to forget about the whole thing and … text output appeeared on the screen.
Wow.
Then the EDID I had was not the correct one for my monitor (I had been messing quite a bit) and a last update did break my bootability, so I flashed the whole thing, this time with jp45.
To my surprise, after forcing HDMI with hotplug, the EDID was read and the whole thing works.
I’ve now a small script /usr/local/etc/hdmi:
#!/bin/sh
echo 1 > /sys/kernel/debug/tegra_hdmi/hotplug
sleep 2
echo 0 > /sys/class/graphics/fb0/blank
sleep 2
and made a systemctl service (/etc/systemd/system/hdmi.service) out of it:
[Unit]
Description=HDMI hotplug disable
After=dbus.service
[Service]
Type=simple
User=root
ExecStart=/bin/sh -c “/usr/local/etc/hdmi”
WorkingDirectory=/tmp
Restart=always
[Install]
WantedBy=multi-user.target
that when enabled makes me happy :) Now I can play with the jetson nano 2GB.
Thanks.
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Thanks a lot, yes it worked for me… my monitor got vga as well as dvi connector. and I used a hdmi to dvi cable (not an adapter, but a full length cable). and it worked perfectly…