DEBUG.md

DEBUG

Debugging weird intermittent reset:

• alarms/timers get disabled

• watchdog timer still working

• UART interrupts still working

• seemed to freeze very quickly with put_led in SSMP::received

  • unexpected interrupt handling chain somewhere??
  • PIO ??

• Timer callback gets stuck when thread is running

• Timer callback stops with uart thread

• Problem with machine.Timer() and _thread on Raspberry Pi Pico (RP2040)

• Repeating timer stops

• alarm pool can appear to stop working

• stdio_uart and stdio_uart_init_full don't play nice with flush

Tests

port	mode	SSMP	TTY	Ok	Notes
USB	NONE	ASN.1+none	-	✓
USB	NONE	ASN.1+ENQ	-	✓
USB	NONE	ASN.1+SEQ	-	✗	Hangs after about an hour
USB	NONE	bisync+SEQ	-	✓
USB	NONE	bisync+GET	-	✓
USB	NONE	ASN.1+SEQ	-	✓	vector without any decoded fields
USB	NONE	ASN.1+SEQ	-	✓	vector without NULL fields
USB	NONE	ASN.1+SEQ	-	✗	vector without vector_new()

RTC	U2	U3	U4	LOG	CLI(USB)	CLI(UART0)	SSMP	Ok	Notes
✗	✗	✗	✗	✗	✗	✗	BER	✓	16hrs , no glitch
✓	✗	✗	✗	✓	✗	✗	BER	✓	8hrs , no glitch
✓	✓	✗	✗	✓	✗	✗	BER	✓	9hrs , no glitch
✓	✓	✓	✗	✓	✗	✗	decode	✓	6hrs , no glitch
✓	✓	✓	✓	✓	✗	✗	decode	✗	glitched

U4

init	setup	relays	LEDs	outputs	monitor	Ok	Notes
✓	x	x	x	x	x	✓
✓	✓	x	x	x	x	✓
✓	✓	✓	x	x	x	✓
✓	✓	✓	x	✓	x	✓
✓	✓	✓	✓	✓	x

Possible causes

• too many get requests

• full queue

• bisync decoder

• UART interrupt handler

• IOX or RTC

• USB

• loop in _print

• CLI TERMINAL_QUERY_STATUS printf

• only occurs with longer SSMP requests

• occasional SSMP echo although message processing is commented out (in reset/BOOTSEL -needs pullups on the TX/RX pins)

• check logic around unpack_sequence and *ix

• corrupted message ??

• something in sequence ?

• check all mutexes are try-lock (priority inversion)

• U3_read ?

• interrupt interrupting interrupt ?

• clocks_enable_resus

• Print out timer registers - [x] 'now'

• Disable RTC update

• Increase request rate

• Mark head/tail as volatile

• Mark head/tail as atomic (https://en.cppreference.com/w/c/language/atomic)

• ... and then maybe make it a queue

TODO

• Check all FIXMEs
• Check that system doesn't freeze when print queue is full
• Maybe only enable SSMP interrupt after a delay?
• bisync max message size
• (?) bisync timeout
• Reinstate watchdog reset

GET

48 41 2 1 0 4 6 112 117 98 108 105 99 160 28 2 2 48 57 2 1 0 2 1 0 48 16 48 14 6 10 43 6 1 4 1 132 128 0 2 1 5 0

48 41 SEQUENCE 2 1 0 INTEGER 0 4 6 112 117 98 108 105 99 STRING public 160 28 PDU GET 2 2 48 57 INTEGER 2 1 0 INTEGER error:0 2 1 0 INTEGER error index:0 48 16 SEQUENCE 48 14 SEQUENCE 6 10 43 6 1 4 1 132 128 0 2 1 OID ".1.3.6.1.4.1.65536.2.1" 5 0 NULL