Dear NVidia Team
We have some systems where we see an issue with “gpioget”. The I2C Expander is connected to I2C2 and the gpiod tools normally work. Now when we add a different I2C device over a cable to the I2C bus (with a different address), we see that the gpioget command sometimes works and sometimes does not work:
$ gpioget 4 0
gpioget: error reading GPIO values: Remote I/O error
$ gpioget 4 0
0
When communicating with the Expander directly with the i2c-tools, we do not see any communication issue.
$ sudo i2cget -y -f 2 0x21
Any idea what could be the issue and how we can solve it?
The I2C Expander is added to i2c@c600000 with the following entry:
tca9554@21 {
compatible = "ti,pca9554";
gpio-controller;
vcc-supply = <&vdd_3v3_cvb>;
gpio-cells = <0x2>;
reg = <0x21>;
status = "okay";
gpio-line-names = "out_b0", "out_b1", "out_b2", "out_b3";
out_b0 {
gpio-hog;
gpios = <0x0 0>;
output-low;
};
out_b1 {
gpio-hog;
gpios = <0x1 0>;
output-low;
};
out_b2 {
gpio-hog;
gpios = <0x2 0>;
output-low;
};
out_b3 {
gpio-hog;
gpios = <0x3 0>;
output-low;
};
};
Thank you for your support.
Kind regards