cdc_acm example doesn't work on nrf52840_pca10059

[markrages]

Describe the bug
CDC_ACM example doesn't work in nrf52840_pca10059. The USB device doesn't appear.

To Reproduce
I build using the workaround in #14945:

1. west build -d build/nRF52/mcuboot -s mcuboot/boot/zephyr -b nrf52840_pca10059 -- -DCONFIG_FLASH_LOAD_OFFSET=0x1000 -DCONFIG_FLASH_LOAD_SIZE=0xf000
2. west build -d build/nRF52/cdc_acm -s zephyrproject/zephyr/samples/subsys/usb/cdc_acm -b nrf52840_pca10059 -- -DCONFIG_FLASH_LOAD_OFFSET=0x10000 -DCONFIG_FLASH_LOAD_SIZE=0x5E000
3. west sign -d build/nRF52/cdc_acm/ -t imgtool -- --key mcuboot/root-rsa-2048.pem
4. Load build/nRF52/mcuboot/zephyr/zephyr.hex and zephyr.signed.hex simultaneously with nRF Connect app.

Expected behavior
A device appears in lsusb output. A tty device appears as /dev/ttyACM*

Actual behavior
No device appears in lsusb. No USB messages appear in dmesg.

Impact
I am stuck in my development without a working serial port.

Environment

• OS: Ubuntu 18.04
• Toolchain: zephyr-sdk-0.10.0
• Commit: c3cf543

[markrages]

Here's backtrace:

#0  0x00017edc in cdc_acm_line_ctrl_get (dev=0x20003764 <__device_cdc_acm_0>, 
    ctrl=4, val=0x2000239c <_main_stack+980>)
    at /home/markrages/zephyr/zephyrproject/zephyr/subsys/usb/class/cdc_acm.c:878
#1  0x0001154c in z_impl_uart_line_ctrl_get (val=0x2000239c <_main_stack+980>, 
    ctrl=4, dev=0x20003764 <__device_cdc_acm_0>)
    at /home/markrages/zephyr/zephyrproject/zephyr/include/uart.h:1112
#2  uart_line_ctrl_get (ctrl=4, val=0x2000239c <_main_stack+980>, 
    dev=0x20003764 <__device_cdc_acm_0>)
    at zephyr/include/generated/syscalls/uart.h:41
#3  main ()
    at /home/markrages/zephyr/zephyrproject/zephyr/samples/subsys/usb/cdc_acm/src/main.c:89

[markrages]

Waiting for DTR is like #13662. Except I am sure the device is plugged in to USB -- that's how I loaded the code.

[jfischer-no]

Except I am sure the device is plugged in to USB -- that's how I loaded the code.

micro USB connector labeled as "nRF USB" is also connected to the host?

[markrages]

@jfischer-phytec-iot the '59 is the dongle, see picture on this unrelated bug: NordicSemiconductor/pc-nrfconnect-programmer#116 (comment)

[markrages]

So, this worked once.

I did the git bisect dance, and learned two things:

1. usb is not working with the nrf52840_pca10059 executables do not work without mcuboot #14945 workaround. Instead compile with west build -d $BUILDDIR -s $SOURCEDIR -b nrf52840_pca10059 -- -DCONFIG_FLASH_LOAD_OFFSET=0x1000 -DCONFIG_FLASH_LOAD_SIZE=0x1f000
2. cdc_acm example works before 5977b3d, and is broken from then on.

[jfischer-no]

Tested with reel board and frdm-k64f, works fine.