I was able to see files when connecting iPhone(10.0.2) to Chromebook.
I was not able to see files when connecting iPhone(10.2) to Chromebook (with the same Chrome OS version).
Upgrading to iOS 10.2 indeed reproduced the issue.

I was able to see files when connecting iPhone(10.2) to Windows 10.
I was not able to see files when connecting iPhone(10.2) to Ubuntu. It says "Unhandled Lockdown error (-20)".
It might be something wrong with either iOS 10.2 or libMTP.

 Issue 682056  has been merged into this issue.

I want to point out that this also affects our Type-C laptops in a more pronounced way because the phone appears to flip between charging and not charging.

This is because whenever the connection is reset, the iPhone drops back down to 100mA current draw at 5V, which it does not consider to be "charging" at all. When it enumerates it pops up to 500mA and repeats.

On other Type-A ports on some Chromebooks this isn't an issue because the ports support BC 1.2 CDP, meaning they support 1.5A always on, so the iPhone charges even through a connection reset.

Tested with Android device as MTP host, and it worked.

Can someone test with 10.3 Beta? I just gotten a Cave and don't have an adapter or hub yet.

Would be helpful to know if 10.3 resolves this (or let Apple know), anyone able to test?

I tried on 10.2.1 and it still does not work :(
Anything we can do on the Chrome OS side?

Something to with openssl? I was poking around Launchpad for Ubuntu and a solution was found for libimobiledevice.

https://bugs.launchpad.net/ubuntu/+source/libimobiledevice/+bug/1623666

Is there any update on this?  iOS 10.2.1 really dislikes the SCP; which is a shame since I do like it...

Any update about this?
We still seeing threads in Community, thx

satorux@ can someone on your team dig deeper on this?

yawano@ is looking at it. if he needs help, maybe tetsui@ could help?

Yes, it's very helpful. tetsui@, could you take a look on this? Thanks.

As this should be an issue in mtpd, changed component to FileManager.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/mtpd/+/69d2cf60165fb74949bb2fb25d918fca743b30b4

commit 69d2cf60165fb74949bb2fb25d918fca743b30b4
Author: Tetsui Ohkubo <tetsui@google.com>
Date: Sat Apr 15 17:56:05 2017

mtpd: Fix iOS 10.2 connectivity issue.

iOS 10.2 device asks a user to tap Allow/Disallow button on the screen
when connected to Chromebook through USB.
Until the button is tapped, Chromebook sees dummy storage on the iOS
device with different storage ID from the actual one.
To handle this properly, LIBMTP_mtpdevice_t should be reused instead
of opening the device every time the storage state changes.

BUG= chromium:676968 
TEST=manually tested.

Change-Id: I01bd262b7dbf381b389cb64dedb546995d73e375
Reviewed-on: https://chromium-review.googlesource.com/474627
Commit-Ready: Kevin Bailey <krb@chromium.org>
Commit-Ready: Tetsui Ohkubo <tetsui@google.com>
Tested-by: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Kevin Bailey <krb@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

[modify] https://crrev.com/69d2cf60165fb74949bb2fb25d918fca743b30b4/device_manager.h
[modify] https://crrev.com/69d2cf60165fb74949bb2fb25d918fca743b30b4/device_manager.cc

Yay! This is a very cool fix. Please merge this to M59 branch as I think this change just missed the branch cut.

We may also want to merge to M58 as this change is small and looks not so risky.

weifangsun@ I would like to hear your opinion on merging to M59 and also M58. Thank you.

tetsui@ - Thanks for fixing this bug!! We should definitely merge this into M59. I do think this fix is important enough to merge into M58 so let's make the request as satorux@ believes it's a lower risk update.

This bug requires manual review: We are only 7 days from stable.
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), bhthompson@(ChromeOS), govind@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Your change meets the bar and is auto-approved for M59. Please go ahead and merge the CL to branch 3071 manually. Please contact milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), gkihumba@(ChromeOS), Abdul Syed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

bhthompson@, can we merge https://chromium-review.googlesource.com/474627 to M58?

- The change is small and looks not so risky (thestig, tetsui, correct me if I'm wrong)
- The changes is only for MTPD (chromiumos/platform/mtpd) and won't affect other parts of Chrome OS
- Re importance, see Comment 21

SGTM for 58.

I cherry-picked this change to

M58: https://chromium-review.googlesource.com/c/482759/
M59: https://chromium-review.googlesource.com/c/481539/

by following the instructions here http://dev.chromium.org/chromium-os/how-tos-and-troubleshooting/working-on-a-branch .

bhthompson@ Let me know if there are additional steps. Thank you.

LGTM, I gave them +2, if you are ready to land them just mark them ready and verified and they should go in.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/mtpd/+/e8e326bcc2e01f423e08da55b2c5601bdc329d58

commit e8e326bcc2e01f423e08da55b2c5601bdc329d58
Author: Tetsui Ohkubo <tetsui@google.com>
Date: Fri Apr 21 01:02:04 2017

mtpd: Fix iOS 10.2 connectivity issue.

iOS 10.2 device asks a user to tap Allow/Disallow button on the screen
when connected to Chromebook through USB.
Until the button is tapped, Chromebook sees dummy storage on the iOS
device with different storage ID from the actual one.
To handle this properly, LIBMTP_mtpdevice_t should be reused instead
of opening the device every time the storage state changes.

BUG= chromium:676968 
TEST=manually tested.

Change-Id: I01bd262b7dbf381b389cb64dedb546995d73e375
Reviewed-on: https://chromium-review.googlesource.com/474627
Commit-Ready: Kevin Bailey <krb@chromium.org>
Commit-Ready: Tetsui Ohkubo <tetsui@google.com>
Tested-by: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Kevin Bailey <krb@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
(cherry picked from commit 69d2cf60165fb74949bb2fb25d918fca743b30b4)
Reviewed-on: https://chromium-review.googlesource.com/482759
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>

[modify] https://crrev.com/e8e326bcc2e01f423e08da55b2c5601bdc329d58/device_manager.h
[modify] https://crrev.com/e8e326bcc2e01f423e08da55b2c5601bdc329d58/device_manager.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/mtpd/+/aef0fb2fbc68007ae8bff20307d9bd041b7327b7

commit aef0fb2fbc68007ae8bff20307d9bd041b7327b7
Author: Tetsui Ohkubo <tetsui@google.com>
Date: Fri Apr 21 01:02:06 2017

mtpd: Fix iOS 10.2 connectivity issue.

iOS 10.2 device asks a user to tap Allow/Disallow button on the screen
when connected to Chromebook through USB.
Until the button is tapped, Chromebook sees dummy storage on the iOS
device with different storage ID from the actual one.
To handle this properly, LIBMTP_mtpdevice_t should be reused instead
of opening the device every time the storage state changes.

BUG= chromium:676968 
TEST=manually tested.

Change-Id: I01bd262b7dbf381b389cb64dedb546995d73e375
Reviewed-on: https://chromium-review.googlesource.com/474627
Commit-Ready: Kevin Bailey <krb@chromium.org>
Commit-Ready: Tetsui Ohkubo <tetsui@google.com>
Tested-by: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Kevin Bailey <krb@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
(cherry picked from commit 69d2cf60165fb74949bb2fb25d918fca743b30b4)
Reviewed-on: https://chromium-review.googlesource.com/481539
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>

[modify] https://crrev.com/aef0fb2fbc68007ae8bff20307d9bd041b7327b7/device_manager.h
[modify] https://crrev.com/aef0fb2fbc68007ae8bff20307d9bd041b7327b7/device_manager.cc

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

This is now fixed and working for me in the stable 58 version.

Verified with iphone 10.3.1 as well. Build: 9334.72.0, 58.0.3029.140