How to monitor nvpmodel GUI voltage drops notification

Hi ,

I am trying to follow https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide%2Fpower_management_nano.html%23wwpID0EPHA

link to detect the system input power drop. first of all i did nit see the desktop notification when i lower the system input power valtage. also could you let me know how to monitor this event as i want to include it in our own App.

thanks

hello terry8uwg2,

you may looking into INA3221 power monitor for these report values.
for example,

31 				channel@0 {
32 					reg = <0x0>;
33 					ti,rail-name = "POM_5V_GPU";
34 					ti,shunt-resistor-mohm = <5>;
35 				};
36 
37 				channel@1 {
38 					reg = <0x1>;
39 					ti,rail-name = "POM_5V_IN";
40 					ti,shunt-resistor-mohm = <5>;
41 				};
42 
43 				channel@2 {
44 					reg = <0x2>;
45 					ti,rail-name = "POM_5V_CPU";
46 					ti,shunt-resistor-mohm = <5>;
47 				};

Thanks. could you explain a little bit more how to monitor ? will kernel monitor these as well and generate some events

hello terry8uwg2,

INA3221 monitors are readable via sysfs nodes, you may check iio_device as below
/sys/devices/50000000.host1x/546c0000.i2c/i2c-6/6-0040/iio_device
for example,

# cat /sys/devices/50000000.host1x/546c0000.i2c/i2c-6/6-0040/iio_device/rail_name_*
POM_5V_IN
POM_5V_GPU
POM_5V_CPU

here’s an example to read POM_5V_CPU voltage, current & power,

# cat /sys/devices/50000000.host1x/546c0000.i2c/i2c-6/6-0040/iio_device/in_current2_input
# cat /sys/devices/50000000.host1x/546c0000.i2c/i2c-6/6-0040/iio_device/in_voltage2_input
# cat /sys/devices/50000000.host1x/546c0000.i2c/i2c-6/6-0040/iio_device/in_power2_input