USB composite CDC-CustomHID device problem, one of I/F hangs or data corruption occurs #274
Description
Brief description
A serious problem with USB composite CDC-CustomHID device working reliably. I have ported your H7 Composite Custom HID - CDC example code to STM32F723 MCU.
HID interface either hangs, sometimes CDC I/F hangs or data integrity fails when running loopback test on both
interfaces at the same time from two different host processes.
Describe the set-up
The board: Not applicable. I was testing with STM32F723-DISCO development board.
IDE: System Workbench for STM32
Observed on Windows 7, 8.1, 10
Describe the bug
I have implemented USB composite CDC- and Custom HID device based on your H7 Composite Custom HID - CDC example code.
HID I/F receives 64 bytes long reports and sends the same reports back to the host running a HID loopback test process .
CDC I/F receives random bytes long packets from length between 1 to 12345 bytes and sends the same data back to the host running loopback test on the same host, however in a different process.
Device enumerates OK with VID 0x483 and PID 0x5741,
If I run test on one interface only it works reliably 247 without any problem.
Once I run loopback test on both interfaces one of the interfaces hangs or incorrect data is received by the host.
Does not matter if the code is running in HS or FS mode.
For simplicity no UART is implemented on CDC side. There is just a simple loopback.
The main loop is not stuck, blinking LED process is still blinking, however processing of comms on USB either CDC or HID is stuck. Looks to me like missing an interrupt processing.
Minimal version of the code is in the attachment.
cdc-hid-min.zip