[ot][spam][crazy] muse-lsl bleak work

[Undiscussed Horrific Abuse, One Victim of Many]

/dev/ttyAMA0 doesn't go away when those things are rmmod'd

# cat /sys/class/tty/ttyAMA0/device/uevent
DRIVER=uart-pl011
OF_NAME=serial
OF_FULLNAME=/soc/serial at 7e201000
OF_COMPATIBLE_0=brcm,bcm2835-pl011
OF_COMPATIBLE_1=arm,pl011
OF_COMPATIBLE_2=arm,primecell
OF_COMPATIBLE_N=3
OF_ALIAS_0=serial1
OF_ALIAS_1=uart0
AMBA_ID=00241011
MODALIAS=amba:d00241011

I'm not finding an 'amba' kernel module, maybe that means it's
compiled in. This looks like it's the source code:
https://github.com/torvalds/linux/blob/master/drivers/tty/serial/amba-pl011.c

I found a quick summary on this page, which rehashes stuff from the
linux tree: https://cateee.net/lkddb/web-lkddb/SERIAL_AMBA.html

If the serial port is straight on the arm chip, which I guess makes
sense, it seems unlikely that it would be a serial port issue. More
likely the chip connected to the serial port, which would mean the
problem would be resolvable inside hciuart.

Part of me is considering trying to put an oscilloscope on the pins. I
have a little cheap pocket oscilloscope.

--

But most likely the problem here is going to be that the chip is in a
nonresponsive state that is documented in its specs manual, and can be
reset by providing some pattern to the port.

This seems really doable now. But also labor intensive.

I guess the chip it is is described by that bcm43xx string, but it
might make sense to look up the specific model number.