esp32c3: can peripheral seems misconfigured as of 0.42.0, transmits return ESP_ERR_INVALID_STATE

[phansel]

Any calls at all to can.transmit(&frame_struct, timeout_u32) will return Err(EspError(259)) aka 0x103 (ESP_ERR_INVALID_STATE) on esp32c3 as of esp-idf-hal 0.42.0 or later. It's not the second or third call, the very first one will do it. can.receive() also doesn't work.

It does not work as of:
esp-idf-hal 0.42
esp-idf-sys 0.33
embuild 0.31.2

It works as of:
esp-idf-hal 0.41.2
esp-idf-sys 0.33
embuild 0.31.2

This is using roughly the api documented in https://github.com/esp-rs/esp-idf-hal/blob/master/src/can.rs:

let peripherals = Peripherals::take().unwrap();
let pins = peripherals.pins;

// filter to accept only CAN ID 881
let filter = can::config::Filter::Standard {filter: 881, mask: 0x7FF };
// filter that accepts all CAN IDs
// let filter = can::config::Filter::standard_allow_all();

let timing = can::config::Timing::B500K;
let config = can::config::Config::new().filter(filter).timing(timing);
let mut can = can::CanDriver::new(peripherals.can, pins.gpio5, pins.gpio4, &config).unwrap();

let tx_frame = can::Frame::new(StandardId::new(0x042).unwrap(), &[0, 1, 2, 3, 4, 5, 6, 7]).unwrap();
can.transmit(&tx_frame, 0_u32);

It doesn't appear to matter whether nightly latest or nightly-2023-07-01 is used for esp-idf-hal 0.42, and I can reproduce on aarch64-apple-darwin and -x86_64-unknown-linux-gnu. nightly latest naturally fails to compile with esp-idf-hal 0.41 due to the AtomicU64 ban.

[phansel]

A workaround to compile against esp-idf-hal 0.41 is to set the toolchain channel to nightly-2023-07-01 or similar.

[Vollbrecht]

if you checkout the API-difference, now you need to do the following before you can use the created can driver, after creating it you need to call start() on it, start() and stop()are separate methods now. You are in an invalid state because you didn't start it

Please try to test it and give feedback if that worked