USB hub multiple devices connection issue

Gangapavan — Tue, 12 May 2026 09:13:53 GMT

I am using an i.MX RT1060 controller in my project development. I am facing issues with USB hub functionality when multiple devices (MSD — pen drive, and CDC — printer) are connected in the following sequence:

Case 1

A) Printer: Attach event occurred and working fine

B) Flash drive:

No attach event is triggered for the flash drive.
When the flash drive is removed, the system hangs inside USB_HostReleaseDeviceResource.

Case 2

A) Flash drive: Connected and working

B) Printer: Attach event occuured, but full interface is not properly completed. It returned error in some port open event call back.

When the flash drive is removed, both devices got disconnected.

Case 3

Both flash drive and printer inserted: Only the flash drive attach event occurred and working.
When the flash drive is removed and reconnected, it works fine.
CDC device connection/disconnection generates no event.
The only way to recover CDC functionality is to restart the system.

Findings:

When I connect the hub to a PC to verify its functionality, both devices are visible in Device Manager. Based on this, I conclude that the issue lies in the USB driver implementation /Composite device handling for USB on the i.MX RT1060.

Is there a way to handle this issue so that both MSD and CDC devices can be reliably enumerated and managed through the hub?

Regards,

Pavan

#IMXRT1060 #nxp #Microcontroller #USB Hub #USB Composite device handling.

MCX MicrocontrollersのトピックUSB hub multiple devices connection issue

USB hub multiple devices connection issue