MTP, libgphoto2 & KFM

[Damon Lynch]

Hello,

I'm developing a FOSS application [1] (Qt 5, python 3.4) that uses 
libgphoto2 to access cameras and camera-like devices, including smart 
phones / tablets that connect via MTP.

I have noticed that when Dolphin has accessed the contents of an MTP 
device, libgphoto2 is unable to access the device, even if Dolphin 
browsing another location e.g. the user's home directory. The device 
becomes free when Dolphin is closed.

To test this, do these steps:

1. To confirm the MTP device is accessible by libgphoto2, plug in an 
unlocked android 4.0 + phone (for example), and from a terminal execute 
gphoto2 --list-folders
     That should work.
2. Open Dolphin and browse some folders on the phone.
3. Repeat step 1 while Dolphin is open. It fails.

I am unaware of a way for the user to do the equivalent of a virtual 
"unmount" to ask Dolphin/Kdeinit5 via the GUI to relinquish exclusive 
control of the device. Is there a way, either through the GUI or the 
command line? GVFS supplies such a feature. I tried solid-hardware 
unmount udi (supplying the correct UDI), but solid-hardware reported the 
MTP device 'does not have the interface StorageAccess".

Is there a way request kdeinit5 to relinquish exclusive control of the 
device from python code? It would be great if my application could 
automatically do a virtual "unmount" of the device so it can access it, 
without user intervention.

Is there a case to be made for KDE applications to provide a virtual 
"unmount" of MTP and perhaps also PTP devices in its GUI?

Thanks.

Damon

[1] https://code.launchpad.net/~dlynch3/rapid/zeromq_pyqt

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