nRF52 USB instability with USB CDC and USB MSC instantiated

[afontaine]

Hello,

I'm working with nRF52840 and SDK v15.2.

I implemented an USB layer with CDC and MSC classes based on nRF examples. All seems to work fine. The USB Serial port is available and I can send/receive data from it. The MSC drive is also properly mounted and I can access it.

But after receiving / sending data over USB serial port for 3, 10 or 15 minutes (it's random), I can't receive data anymore.

Looking at the USB event, I don't receive APP_USBD_CDC_ACM_USER_EVT_RX_DONE event reported from cdc_acm_user_ev_handler. But I noticed I receive APP_USBD_EVT_DRV_RESET event from USBD User defined event processor handler. 

The issue doesn't appear if USB MSC class is not instantiated.

Do you have any idea how to solve this issue ?

Best regards,

Aurélie

[Constantin]

We are facing the similar issue. If we write to the SDCard there is no error. But if we plugin the USB connection and read the data via msc the data sometimes is corrupted meaning lines are deleted or repeated spuriosly.

But if we plugin the SD card directly to the PC there is no corruption.

Any reason for this?

Current SDK version 15.3.

[Jørgen Holmefjord]

Can you provide more details on how this issue looks, and post log files, example of corrupted files, etc, and include details about your system environment.

[Constantin]

We just found the solution and it seems to be a fix for https://devzone.nordicsemi.com/f/nordic-q-a/39428/usb-msc-corruption/167555 as well.

We just found out that the file is not corrupted during writing to SD card but when read from SD Card via USB msc interface. If we just plugged in the SD card to our PC the file was completely correct. But if we read it via USB msc the file hat spurious corruptions.

Our fix for the moment was to increase the MSC_WORKBUFFER_SIZE to 2048 bytes.

For now the error did not occur anymore.