Transferring lots of data to nRF can cause crash

[jepler]

To trigger, I run dd if=/dev/zero bs=512 count=200 of=/media/jepler/CIRCUITPY/zero.

With a debug build, I can capture this traceback:

Breakpoint 4, reset_into_safe_mode (reason=reason@entry=GC_ALLOC_OUTSIDE_VM)
    at ../../supervisor/shared/safe_mode.c:84
84	void __attribute__((noinline,)) reset_into_safe_mode(safe_mode_t reason) {
(gdb) where
#0  reset_into_safe_mode (reason=reason@entry=GC_ALLOC_OUTSIDE_VM)
    at ../../supervisor/shared/safe_mode.c:84
#1  0x00027dc4 in gc_alloc (n_bytes=n_bytes@entry=64, 
    has_finaliser=has_finaliser@entry=false, long_lived=<optimized out>)
    at ../../py/gc.c:489
#2  0x000274ec in m_malloc_maybe (num_bytes=num_bytes@entry=64, 
    long_lived=long_lived@entry=false) at ../../py/malloc.c:95
#3  0x00047f86 in allocate_ram_cache ()
    at ../../supervisor/shared/external_flash/external_flash.c:327
#4  0x000482f4 in external_flash_write_block (
    data=data@entry=0x200047e4 <_mscd_buf> "", block=block@entry=203)
    at ../../supervisor/shared/external_flash/external_flash.c:518
#5  0x0004839e in supervisor_flash_write_blocks (
    src=0x200047e4 <_mscd_buf> "", block_num=203, num_blocks=2)
    at ../../supervisor/shared/external_flash/external_flash.c:554
#6  0x00043c9a in flash_write_blocks (src=<optimized out>, 
    block_num=<optimized out>, num_blocks=<optimized out>)
    at ../../supervisor/shared/flash.c:121
#7  0x00042bb4 in disk_write (pdrv=pdrv@entry=0x200044e4 <_internal_vfs>, 
    buff=buff@entry=0x200047e4 <_mscd_buf> "", sector=sector@entry=204, 
    count=count@entry=2) at ../../extmod/vfs_fat_diskio.c:120
#8  0x0004ad58 in tud_msc_write10_cb (lun=<optimized out>, lba=204, 
    offset=<optimized out>, buffer=buffer@entry=0x200047e4 <_mscd_buf> "", 
    bufsize=bufsize@entry=1024)
    at ../../supervisor/shared/usb/usb_msc_flash.c:140
#9  0x00049b26 in mscd_xfer_cb (rhport=<optimized out>, 
    ep_addr=<optimized out>, event=<optimized out>, xferred_bytes=1024)
    at ../../lib/tinyusb/src/class/msc/msc_device.c:474
#10 0x0004920a in tud_task () at ../../lib/tinyusb/src/device/usbd.c:330
#11 0x0004ac3e in usb_background () at ../../supervisor/shared/usb/usb.c:79
#12 0x0004b098 in run_background_tasks () at background.c:61
#13 0x0005acea in common_hal_neopixel_write (
    digitalinout=digitalinout@entry=0x20004774 <status_neopixel>, 
    pixels=pixels@entry=0x2000477c <status_neopixel_color> "\v", 
    numBytes=numBytes@entry=3) at common-hal/neopixel_write/__init__.c:203
#14 0x00043de4 in clear_temp_status ()
    at ../../supervisor/shared/rgb_led_status.c:300
#15 0x00047f1e in spi_flash_flush_keep_cache (
    keep_cache=keep_cache@entry=false)
    at ../../supervisor/shared/external_flash/external_flash.c:444
#16 0x00048190 in supervisor_flash_release_cache ()
    at ../../supervisor/shared/external_flash/external_flash.c:455
#17 0x00043aee in filesystem_flush ()
    at ../../supervisor/shared/filesystem.c:127
#18 0x000430fa in start_mp (heap=heap@entry=0x200063c0 <allocations+16>)
    at ../../main.c:116
#19 0x000432aa in run_code_py (safe_mode=safe_mode@entry=NO_SAFE_MODE)
    at ../../main.c:240
#20 0x000435a2 in main () at ../../main.c:464

At this point, the device disconnects from USB and the indicator blinks yellow until reset.

[jepler]

This is a duplicate of #2338 but the discussion there is better.