STM32F413 USB Device no longer enumerates after some time

[acurana_chris]

Hello,

we are using the ST USB Stack in Device mode in an F413 project with a CDC Device Class (STMicroelectronics Virtual COM Port).
Both HAL and USB Stack code are from ST github at https://github.com/STMicroelectronics/stm32-mw-usb-device.git and https://github.com/STMicroelectronics/stm32f4xx_hal_driver, so should be the latest version.

It is a self(battery) powered device and we are using vbus sensing on PA9.
The project was initially CubeMx generated. MX_USB_DEVICE_Init is called once after startup.

In general the USB Stack works, but we are facing one serious problem:

After some time, could be hours or days when the device was not plugged in (or just connected to a USB charger), when the device is then reconnected to a PC (Linux or Windows) the device is no longer recognized/enumerated by the host.

Windows is showing some error; under Linux we see some error code in the log.

There is some power drawn from the USB, we verified that it is below 100mA so that should be ok.

In oder to understand what is happening we put in some debug code in the HAL_PCD_IRQHandler which logs the IRQs. The debug code just logs the interrupts to a buffer, the log printout  (on UART) is then done later completely independent from HAL_PCD_IRQHandler so the USB ISR is not affected timing-wise.

When this problem of "not being able to enumerate" happens we see the below sequence of interrupts. It seems that the Suspend/Resume is triggered all the time. When the device is then unplugged and re-plugged the same thing happens again. It seems the USB Stack or the OTG hardware is stuck somehow. The only way to make the device enumerate properly again is to reset the device.

How can this happen? Is there something in the USB Stack that could lead to this situation? Could it be the OTG peripheral that gets stuck somehow?
Very strange.

Any hint what we could do to fix that problem is very much appreciated!

Many thanks in advance
Chris
Embedded FW developer, acurana GmbH

USB interrupts when the "unable to enumerate" happens
=====================================================

USB: IRQ: Session request/new session detected interrupt
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: ConnectCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB suspend
USB: IRQ: USB reset
USB: IRQ: Enumeration done
USB: ResetCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB suspend
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB suspend
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB suspend
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB suspend
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB suspend
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB suspend
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB suspend
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB reset
USB: IRQ: Enumeration done
USB: ResetCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: Resume/remote wakeup detected interrupt
USB: ResumeCB
USB: IRQ: USB suspend
USB: IRQ: Resume/remote wakeup detected interrupt
...
(keeps going for some time, then eventually stops)

USB Stack init settings
=======================

USBD_StatusTypeDef USBD_LL_Init(USBD_HandleTypeDef *pdev)
{
/* Init USB Ip. */
if (pdev->id == DEVICE_FS) {
/* Link the driver to the stack. */
hpcd_USB_OTG_FS.pData = pdev;
pdev->pData = &hpcd_USB_OTG_FS;

hpcd_USB_OTG_FS.Instance = USB_OTG_FS;
hpcd_USB_OTG_FS.Init.dev_endpoints = 6;
hpcd_USB_OTG_FS.Init.speed = PCD_SPEED_FULL;
hpcd_USB_OTG_FS.Init.dma_enable = DISABLE;
hpcd_USB_OTG_FS.Init.phy_itface = PCD_PHY_EMBEDDED;
hpcd_USB_OTG_FS.Init.Sof_enable = DISABLE;
hpcd_USB_OTG_FS.Init.low_power_enable = DISABLE;
hpcd_USB_OTG_FS.Init.lpm_enable = DISABLE;
hpcd_USB_OTG_FS.Init.battery_charging_enable = DISABLE;
hpcd_USB_OTG_FS.Init.vbus_sensing_enable = ENABLE;
hpcd_USB_OTG_FS.Init.use_dedicated_ep1 = DISABLE;