Enum ProtocolError 

#[non_exhaustive]
pub enum ProtocolError {
    UnknownFrlRate(u8),
    FfeLevelsOutOfRange {
        rate: HdmiForumFrl,
        levels: u8,
    },
}

What culvert refuses because it would violate the SCDC protocol.

Every value a sink can report decodes (an undefined link training request is LtpReq::Reserved), so these come from requests, not from register content.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

UnknownFrlRate(u8)

The sink reported an FRL rate value not defined by the HDMI 2.1 specification.

The inner value is the raw 4-bit field read directly from the SCDC register. It is exposed so callers can log or diagnose misbehaving sinks, not because it carries semantic meaning — any value outside the spec-defined set is treated as a protocol violation regardless of its numeric value.

Not currently returned: no culvert method reads an FRL rate back from the sink.

FfeLevelsOutOfRange

The requested FFE levels exceed the maximum allowed at the requested FRL rate (see FfeLevels::max_for). A sink treats a prohibited value as 0, so it is rejected before anything is written.

Fields

rate: HdmiForumFrl

The requested FRL rate.

levels: u8

The requested FFE levels.

Trait Implementations

impl Debug for ProtocolError

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.