Invalid CAN/TWAI Alert values

[4rzael]

Bug description

I believe the CAN Alert type is wrongly defined.

As seen here, it is built using EnumSet.
The corresponding definition in esp-idf is here

I believe there is a 1-bit offset in the definition, due to 1-indexing instead of 0-indexing.
In other places in the codebase (eg: the UART driver), we can see 0-indexing is used.

• Would you like to work on a fix?

I can make a PR if needed, if you agree this is indeed wrong

To Reproduce

As an example, using the following:

dbg!((Alert::BusRecovered | Alert::ReceiveQueueFull | Alert::BusOffline).as_repr())

prints

(Alert::BusRecovered | Alert::ReceiveQueueFull | Alert::BusOffline).as_repr() = 20608

Looking at the ReceiveQueueFull bit, we should have 0x800 set (see definition in esp-idf).

> hex(20608)
0x5080
> 0x5080 & 0x800
0
> 0x5080 & 0x1000
4096

Moreover, I can see the problem in application code: I need to set Alert::TransmitFailed instead of Alert::ReceiveQueueFull to receive alerts when loosing an incoming frame.

Expected behavior

The Alert EnumSet should match the values in esp-idf.

Environment

• Crate (esp-idf-hal) version: 0.45.2
• ESP-IDF branch or tag: v5.4
• Target device (MCU): esp32s3
• OS: MacOS 15.0

[Vollbrecht]

good catch! Yeah the enumset wants a "bitpositon" and not a literal value. So starting with 0 would be correct, as the TransmitIdle bit should be stored in the zero position.

[Vollbrecht]

Feel free to send a PR and add a note to the CHANGELOG.md, otherwise i update it later.