First of all, both FX30 3G and FX30 LTE works well.
The issue is seen only in MangOH Red b/d. The only issue in MangOH b/d is the USB2Serial data communication. Anything else works well - 1) bring-up, 2) flashing the latest FW, 3) AT command access through /dev/ttyAT, 4) LTE cellular connection with Zipit AT&T test SIM, 5) IP connection and operation over the underlying cellular connection
Let me share more about USB2Serial communication failure issue in MangOH b/d.
- Renfell USB Host IoT Expansion Card isn’t detected or recognized through MangOH IoT b/d slot.
In FX30 LTE b/d,
I could see the following kernel log when USB host card is inserted into FX30 LTE b/d
diag: USB channel diag connected
msm_otg 78d9000.usb : Avail curr from USB = 500
QTI : USB tethered modem SMD port opened
QTI : ECM mode
QTI : LINK_UP Processed
QTI : LINK_UP message_posted.
However no kernel log change when USB host card is inserted into MangOH b/d and doesn’t work at all.
2) The FTDI device connection/recognition through USB Host connector in MangOH b/d is OK. However the data communication through USB2Serial driver makes the communication error – TTY_BREAK is seen continuously at ftdi_sio driver level(FTDI_RS_BI). it generates NULL data report to the upper layer. It isn’t seen in FX30 LTE b/d. It is suspected that USB3503 Hub connection on MangOH b/d is different from the USB logic in FX30 LTE b/d. We’d like to compare the USB logic between MangOH b/d and FX30 LTE b/d.
Does anybody have the similar experience?
I also wonder if MangOH Red b/d specific device tree configuration(dts, dtsi etc.) and kernel configuration to load all the necessary drivers especially the external USB Hub chip(USB3503). I managed to load usb3503 driver by adding dts entry and kernel config but it seems it doesn’t work as well.