Hello,
I’m using a Jetson TX2 NX SOM on a custom carrier board with the Lontium lt6911uxc chip, and while the kernel log output and I2C comms look good I’m not able to use any of the v4l2 commands (v4l2-ctl
, v4l2-dbg
, and v4l2-compliance
). Any of those commands will hang immediately, and we’re not certain if the issue is with the device tree or with something else.
An example of trying a v4l2 command:
user@devhost:~$ v4l2-dbg -d /dev/video0 -n --verbose
The empty line at the end is all we see on our end, and the return from ps aux | grep v4l2
shows the v4l2 command in state ‘D+’.
Our dmesg output for the chip looks fine to us:
user@devhost:~$ dmesg | grep lt6911
[ 13.490317] lt6911uxc 9-002b: probing lt6911uxc v4l2 sensor at addr 0x2b
[ 13.499652] lt6911uxc 9-002b: mclk absent,assuming sensor driven externally
[ 13.512244] lt6911uxc 9-002b: tegracam sensor driver:lt6911uxc_v2.0.6
[ 13.514697] tegra-vi4 15700000.vi: subdev lt6911uxc 9-002b bound
[ 13.525009] Modules linked in: lt6911uxc(+) nvgpu ip_tables x_tables
[ 13.714031] [<ffffff8000f8ba2c>] lt6911uxc_probe+0x124/0x238 [lt6911uxc]
[ 13.765852] [<ffffff8000f8f018>] lt6911uxc_i2c_driver_init+0x18/0x30 [lt6911uxc]
[ 15.296919] Modules linked in: zram userspace_alert lt6911uxc(+) nvgpu ip_tables x_tables
And here’s our (decompiled) device tree for the i2cmux and lt6911uxc:
cam_i2cmux {
compatible = "i2c-mux-gpio";
#address-cells = <0x1>;
#size-cells = <0x0>;
i2c-parent = <0x45>;
mux-gpios = <0x21 0x14 0x0>;
i2c@0 {
clock-frequency = <0x186a0>;
reg = <0x0>;
#address-cells = <0x1>;
#size-cells = <0x0>;
linux,phandle = <0x159>;
phandle = <0x159>;
lt6911uxc_a@2b {
compatible = "nvidia,lt6911uxc";
reg = <0x2b>;
status = "okay";
devnode = "video0";
reset-gpios = <0x21 0x69 0x1>;
interrupt-parent = <0x23>;
interrupts = <0x32 0x4>;
linux,phandle = <0x15a>;
phandle = <0x15a>;
ports {
#address-cells = <0x1>;
#size-cells = <0x0>;
port@0 {
ret = <0x0>;
status = "okay";
endpoint {
status = "okay";
port-index = <0x0>;
bus-width = <0x4>;
remote-endpoint = <0xd0>;
linux,phandle = <0x4d>;
phandle = <0x4d>;
};
};
};
};
};
};