We have a custom carrier board on which the HDMI is not working. Originally, we did not have the i2C GPIO port expander. However, we have since dead bugged the ic on the board, connecting only connected the HDMI_PWR_EN pin. This corrected one of the issues (incidentally, also kick started USB - separate issue). The issue now is that we are not getting any SCL or SDA signal from the TX2. We have verified that the detect signal from the HDMI monitor is being asserted to the TX2 and that the HDMI power is on. Also, we have the level shifter with the TX2 side pulled up to 3.3V and the connector side to 5V.
nvidia@tegra-ubuntu:~$ dmesg | grep tegradc
[ 0.458146] tegradc 15210000.nvdisplay: DT parsed successfully
[ 0.458177] tegradc 15210000.nvdisplay: Display dc.ffffff8002320000 registered with id=0
[ 0.465635] tegradc 15210000.nvdisplay: vblank syncpt # 7 for dc 1
[ 0.465650] tegradc 15210000.nvdisplay: vpulse3 syncpt # 8 for dc 1
[ 0.468169] tegradc 15210000.nvdisplay: hdmi: no prod_list_hdmi_board, use default range
[ 0.474483] tegradc 15210000.nvdisplay: probed
[ 2.645998] tegradc 15210000.nvdisplay: fb registered
[ 9.105036] tegradc 15210000.nvdisplay: blank - powerdown
I’ve verified that the UART1_TX pin is low until after the carrier power on signal from the TX2 is high. There is a delay of around 600ms. I don’t know if this is too long or if it doesn’t matter.
Anyone have similar issue or a possible solution?