Enum PtpError 

pub enum PtpError {
    Usb(Error),
    Protocol {
        code: ResponseCode,
        operation: OperationCode,
    },
    InvalidData {
        message: String,
    },
    Io(Error),
    Timeout,
    Disconnected,
    SessionNotOpen,
    NoDevice,
    Cancelled,
    DeviceReset,
}

The main error type for mtp-rs operations.

Variants

Usb(Error)

USB communication error

Protocol

Protocol-level error from device

Fields

code: ResponseCode

The response code returned by the device.

operation: OperationCode

The operation that triggered the error.

InvalidData

Invalid data received from device

Fields

message: String

Description of what was invalid.

Io(Error)

I/O error

Timeout

Operation timed out

Disconnected

Device was disconnected

SessionNotOpen

Session not open

NoDevice

No device found

Cancelled

Operation cancelled

DeviceReset

A transfer cancel wedged the device, and the transport was reset to recover it. The PTP session is gone; reopen the device to continue.

Seen when cancelling or abandoning an in-flight read on an Android device (issue #18): the device stops responding, so cancel_transfer issues a USB DEVICE_RESET and reports this instead of a false success. Transfer size doesn’t drive it; a 36-byte file is enough.

Don’t treat this as the only wedge signature. A Samsung reports it; a Pixel wedges the same way but the next operation simply hangs with no error at all (verified on a Pixel 9 Pro XL, macOS/nusb, 2026-07-20), so wrap operations in a timeout as well as matching this variant. See docs/notes/android-wedges-and-the-reset-kill-switch.md.

Implementations

impl PtpError

pub fn invalid_data(message: impl Into<String>) -> Self

Create an invalid data error with a message.

pub fn is_retryable(&self) -> bool

Check if this is a retryable error.

Retryable errors are transient and the operation may succeed if retried:

• DeviceBusy: Device is temporarily busy
• Timeout: Operation timed out but device may still be responsive

pub fn response_code(&self) -> Option<ResponseCode>

Get the response code if this is a protocol error.

pub fn is_exclusive_access(&self) -> bool

Check if this error indicates another process has exclusive access to the device.

This typically happens on macOS when ptpcamerad or another application has already claimed the USB interface. Applications can use this to provide platform-specific guidance to users.

Example

match device.open().await {
    Err(e) if e.is_exclusive_access() => {
        // On macOS, likely ptpcamerad interference
        // App can query IORegistry for UsbExclusiveOwner to get details
        show_exclusive_access_help();
    }
    Err(e) => handle_other_error(e),
    Ok(dev) => use_device(dev),
}

Trait Implementations

impl Debug for PtpError

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

Formats the value using the given formatter.

impl Display for PtpError

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

Formats the value using the given formatter.

impl Error for PtpError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<Error> for PtpError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<PtpError> for Error

fn from(e: PtpError) -> Self

Converts to this type from the input type.

impl From<PtpUploadError> for PtpError

fn from(e: PtpUploadError) -> Self

Converts to this type from the input type.