Feedback: Working devices - no test failures.

[juleskers]

Hi @vdavid, Kudos to you for taking this on. The state of MTP can be better, so I'm happy to see someone starting a new implementation 🧡

Your contributing-guidelines request opening issues if any tests don't work. But I believe you'd also be happy to hear about things that DO work. After all, positive feedback is feedback too!

To avoid being cluttered with "device XYZ works" issues. I propose this issue/thread as a place where people can report "I tested with device XYZ, and it worked, no problems."

If you'd prefer separate feedback into different issues, of course feel free to close this issue.
After all, it's your project 🧡

[vdavid]

I don't feel strongly either way, your proposal makes sense, so let's go with this! Also thanks for the nice words 🙂
Did you test the lib with any new devices by any chance?

[juleskers]

In fact I did! I was writing it up as a separate comment.
I also have a midling-old compact camera lying in a drawer somewhere. I'll see if I can dig that out somewhere this week.

Positive tests: Fairphone 5, running e/OS/

• Android 13 base; LineageOS derived
• e/OS/ build: 3.0.4-t-20250710507811-community-FP5
• Host device: Desktop computer, running Linux (OpenSuse Tumbleweed; kernel 6.19.8-1-default).
• mtp-rs tag: v0.11.0, git commit 62779a8
• rustc --version = rustc 1.94.1 (e408947bf 2026-03-25)

Small side note:
The host computer auto-mounted the MTP folder upon connecting, I had to first un-mount it from the file explorer, before the tests would run. (Otherwise, got error open device failed: Usb(Error { kind: Busy, code: Some(16), message: "interface is busy" })

Tests ran:

• Read-only:
  cargo test --test integration readonly -- --ignored --nocapture --test-threads=1
test result: ok. 11 passed; 0 failed; 0 ignored; 0 measured; 6 filtered out; finished in 1.30s

  • readonly::slow_test_list_recursive - SKIPPING
  • readonly::test_cancel_download_then_reuse_session
  • readonly::test_custom_timeout
  • readonly::test_device_connection
  • readonly::test_download_with_progress
  • readonly::test_drop_mid_stream_then_software_reconnect - SKIPPING: requires --release
  • readonly::test_list_root_folder
  • readonly::test_list_storages
  • readonly::test_ptp_device
  • readonly::test_refresh_storage
  • readonly::test_streaming_download

• read-only + destructive (full suite)
  cargo test --test integration -- --ignored --nocapture --test-threads=1
test result: ok. 16 passed; 0 failed; 0 ignored; 0 measured; 1 filtered out; finished in 1.91s

  • destructive::test_create_delete_folder
  • destructive::test_rename_file
  • destructive::test_streaming_copy
  • destructive::test_streaming_upload
  • destructive::test_upload_download_delete
  • readonly::slow_test_list_recursive SKIPPING
  • readonly::test_cancel_download_then_reuse_session
  • readonly::test_custom_timeout
  • readonly::test_device_connection
  • readonly::test_download_with_progress
  • readonly::test_drop_mid_stream_then_software_reconnect - SKIPPING: requires --release
  • readonly::test_list_root_folder
  • readonly::test_list_storages
  • readonly::test_ptp_device
  • readonly::test_refresh_storage
  • readonly::test_streaming_download

• full suite - release profile (for the skipped drop-mid-stream)
  cargo test --release --test integration readonly -- --ignored --nocapture --test-threads=1

  • previous tests, same as before
  • drop-mid-stream goes bad: runs into timeouts, and the remaining tests then fail too, until I disconnect the cable and reconnect.

   test readonly::test_drop_mid_stream_then_software_reconnect ... [00:00:00.620] Searching for file (100KB-10MB)...
   [00:00:00.750] Starting download of Center Parcs Limburgse Peel - Cottage_Manual_MD.pdf (5180416 bytes)
   [00:00:00.761] Read 65524 bytes (1.3%), now dropping without cancel...
   [00:00:00.761] Dropped mid-stream (no cancel, no drain)
   [00:00:00.761] Attempting software reconnect...
   [00:00:30.764] Software reconnect FAILED at open: Timeout
   ok
   test readonly::test_list_root_folder ... [00:01:00.767] SKIPPING: open device - Timeout
   [00:01:00.767]   Check: phone unlocked? USB authorized? Cable connected?
   ok

[vdavid]

FYI, added Fairphone 5 to the list of tested phones here.

[dasJ]

My Garmin Forerunner 955 works as well. The test suite is not really happy (I assume Garmin's botched MTP interface is at fault here) but I got it to work in an actual application.

The only quirk I found was that I had to set device.session().set_split_header_data(true); for uploads to succeed.

[vdavid]

Wow, nice, @dasJ! I didn't know Garmin watches used MTP.
I happen to use a Forerunner 55, so I could just try connecting it, but I'd need a USB-C/USB converter for it which I lack due to ongoing travels.
But if you have a PR that makes it work for yours and you attach the test results, happy to take it!