hid-service: add timeout for I2C device operations

[jerrysxie]

This pull request introduces configurable timeout handling for I2C HID device and host operations, replacing hardcoded timeouts with new Config structs. This change allows users to customize operation timeouts and improves error handling by reporting specific timeout errors. The update also modifies all usages of the device and host constructors to accept these new configuration parameters, ensuring consistent timeout management throughout the codebase.

Timeout configuration and usage improvements:

• Added Config structs for both Device and Host in hid-service/src/i2c/device.rs and hid-service/src/i2c/host.rs, allowing customization of timeouts for device response and data reads. Default values are provided. [1] [2]
• Updated Device and Host constructors to accept a timeout configuration parameter, and refactored all internal timeout usages to reference these configuration values instead of hardcoded constants. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15]

Error handling enhancements:

• All I2C operations in Device now use the with_timeout wrapper, returning a specific timeout error if the operation exceeds the configured duration and logging the error for better traceability. [1] [2] [3] [4]

API and macro updates:

• Updated public exports in hid-service/src/i2c/mod.rs to include the new Config types as DeviceConfig and HostConfig.
• Modified macros and static initializations in hid-service/src/i2c/passthrough/mod.rs and keyboard-service/src/task.rs to use the new constructors and pass default timeout configurations. [1] [2] [3]

[Copilot]

Pull request overview

This PR adds bounded timeouts around all I2C master operations performed by the HID I2C device side, preventing indefinite blocking when devices misbehave or stop responding.

Changes:

• Introduced DEVICE_RESPONSE_TIMEOUT_MS (200 ms) and DATA_READ_TIMEOUT_MS (50 ms) in the I2C device implementation.
• Wrapped all bus.write_read, bus.read, and bus.write calls in hid-service/src/i2c/device.rs with embassy_time::with_timeout, mapping timeout expiries to Error::Hid(hid::Error::Timeout).
• Added per-call logging for timeout vs. underlying bus errors for descriptor reads, report descriptor reads, input reports, and command/host-data transfers.

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[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

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[tullom]

Two nb comments, otherwise lgtm!

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

Comments suppressed due to low confidence (1)

hid-service/src/i2c/host.rs:83

• Both read_bus and write_bus log the same "Response timeout" message on timeout, which makes it hard to tell whether the host timed out on a write vs read. Consider using distinct messages (or include operation context) so logs are actionable.

    async fn read_bus(&self, timeout: Duration, buffer: &mut [u8]) -> Result<(), Error<B::Error>> {
        let mut bus = self.bus.lock().await;
        with_timeout(timeout, bus.respond_to_write(buffer))
            .await
            .map_err(|_| {
                error!("Response timeout");
                Error::Hid(hid::Error::Timeout)
            })?
            .map_err(|e| {
                error!("Failed to read from bus");
                Error::Bus(e)
            })
    }

    async fn write_bus(&self, timeout: Duration, buffer: &[u8]) -> Result<(), Error<B::Error>> {
        let mut bus = self.bus.lock().await;
        // Send response, timeout if the host doesn't read so we don't get stuck here
        trace!("Sending {} bytes", buffer.len());
        with_timeout(timeout, bus.respond_to_read(buffer))
            .await
            .map_err(|_| {
                error!("Response timeout");
                Error::Hid(hid::Error::Timeout)
            })?

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[williampMSFT]

[jerrysxie]

Announced API changes on Zulip: #embedded-controller > hid-service API breaking changes @ 💬