Jetson Nano I2C Bind/Unbind

[sumin.lee1]

Hello,

Our custom board, there is a hanging while we use i2c-3(7000c700.i2c)

So, we tried to unbind and bind for i2c-3(7000c700.i2c) but it doesn’t works.

And then Now I’m trying to test same process on Jetson Nano Developer Kit.
I am just testing it as default status. This status has no issue with any i2c bus.
The other i2c buses are working to unbind/bind what I can access.

But there is no result for unbinding i2c-3. Terminal is juststopped.

And I can’t find i2c-3 bus on the other terminal.

And No such devices is out when I try to bind.

Is anyone know why it doesn’t works?

[ShaneCCC]

Will update to your for checking internally.

Thanks

[sumin.lee1]

Hello, Could I get any update ??

[ShaneCCC]

What’s your BSP version.
I can’t see the problem on my device.

root@tegra-ubuntu:/sys/bus/platform/drivers/tegra-i2c# cat /etc/nv_tegra_release
# R32 (release), REVISION: 7.3, GCID: 31982016, BOARD: t210ref, EABI: aarch64, DATE: Tue Nov 22 17:30:08 UTC 2022
root@tegra-ubuntu:/sys/bus/platform/drivers/tegra-i2c#
root@tegra-ubuntu:/sys/bus/platform/drivers/tegra-i2c#
root@tegra-ubuntu:/sys/bus/platform/drivers/tegra-i2c#
root@tegra-ubuntu:/sys/bus/platform/drivers/tegra-i2c# ll
total 0
drwxr-xr-x   2 root root    0 Dec 23 22:03 ./
drwxr-xr-x 216 root root    0 Dec 23 22:01 ../
lrwxrwxrwx   1 root root    0 Dec 23 22:01 7000c000.i2c -> ../../../../devices/7000c000.i2c/
lrwxrwxrwx   1 root root    0 Dec 23 22:01 7000c400.i2c -> ../../../../devices/7000c400.i2c/
lrwxrwxrwx   1 root root    0 Dec 23 22:01 7000c500.i2c -> ../../../../devices/7000c500.i2c/
lrwxrwxrwx   1 root root    0 Dec 23 22:04 7000c700.i2c -> ../../../../devices/7000c700.i2c/
lrwxrwxrwx   1 root root    0 Dec 23 22:01 7000d000.i2c -> ../../../../devices/7000d000.i2c/
lrwxrwxrwx   1 root root    0 Dec 23 22:01 7000d100.i2c -> ../../../../devices/7000d100.i2c/
--w-------   1 root root 4096 Dec 23 22:03 bind
--w-------   1 root root 4096 Dec 23 22:01 uevent
--w-------   1 root root 4096 Dec 23 22:03 unbind
root@tegra-ubuntu:/sys/bus/platform/drivers/tegra-i2c# echo 7000c700.i2c > unbind
root@tegra-ubuntu:/sys/bus/platform/drivers/tegra-i2c# echo 7000c700.i2c > bind
root@tegra-ubuntu:/sys/bus/platform/drivers/tegra-i2c#

[sumin.lee1]

I tried to test several combinations
But Nothing works.

- Jetson Nano Developer Kit, JetPack 4.6.4

- Jetson Nano Developer Kit, JetPack 4.6.3

- Jetson Nano Production Module + Seeed J101, JetPack 4.6.4

- Jetson Nano Production Module + Seeed J101, JetPack 4.6

- Jetson Nano Production Module + Seeed J101, JetPack 4.5.1

[sumin.lee1]

Is there any other way to reset I2C device about same port (7000c700)??

[ShaneCCC]

Do you have any modify for the device tree or have any slave device on this bus?

[sumin.lee1]

At beginning of test, we did it on custom board and custom kernel.
Last one, we were flashing just default BSP.

[ShaneCCC]

Default BSP on customize board? Could you check on devkit.

Thanks

[sumin.lee1]

Sorry, It means as follow:
Back then, Custom BSP => Custom Board
Now days, Default BSP => Dev Kit (You can see what system I used on the capture images)

[ShaneCCC]

I have confirm on two Nano without problem.
Do you have another Nano devkit to confirm.

Thanks

[sumin.lee1]

I tested several boards as following:

• Jetson Nano A02 Dev Kit
• Jetson Nano B01 Dev Kit
• Jetson Nano B01 Production Module.

And Our customer has same problem with their Jetson Nano custom board.

[ShaneCCC]

Could you check the dmesg if any error.

[sumin.lee1]

I can’t see anything releated to I2C Unbind/Bind error.
nano dev-kit i2c bind error dmesg.txt (57.9 KB)

[sumin.lee1]

I’ve got answer.
It can work when HDMI connector is unpluged.
Thank you for the support.

[ShaneCCC]

It looks like this i2c is used by display hdmi.
and if you have display connected, it will fail and cause system hang.