Samsung S5 phone from my Plasma5 desktop.
When I plug the phone in, I get the notification with 2 suggested
actions. They both read "Open with File Manager" but the first one
opens Dolphin with "camera:..." while the second opens Dolphin with
"mtp:..." in the location bar. When I actually try to navigate to the
folder with my photos, I get a notification on the phone telling me a
device is attempting mtp access... When I click "Allow", I get another
notification pop-up on my desktop with the same two options...
When I actually try to access the photos, I frequently get "process
died" or "I/O error" messages, although sometimes I can actually see a
photo (not just the file names) - persistence pays off. Moreover the
phone will lock when connected, even if a file transfer is underway.
This kills the transfer.
To make matters worse, I have photos and videos that I have taken
which show up in the Gallery on the phone and which I can view on the
phone and see when I remove the SD card and read it directly but which
don't show up in Dolphin.
Clearly this is not the way the process is supposed to work. I can
understand the phone requesting a verification for the connection, but
everything on the desktop side seems wrong:
- the two actions should be distinguishable by their description,
- the process shouldn't die and if it does, it should relaunch,
- the connection should block the phone from locking if locking will
stop file transfers,
- there should be a record of the error in a log somewhere. As it is,
all I can find is a lot of systemd journal entries like "Jan 24
14:01:33 transponder kernel: usb 4-5: usbfs: process 20598 (mtp.so)
did not claim interface 0 before use" which seem to occur before the
device is actually recognized.
- all the photos should show up
It sounds like you want to offload files from your android. For a few
years now I've been using Software Data Cable to do this, free app, no
cable needed. Launch the app and it sets up an ftp server on the
phone. Then from my laptop I log in, navigate, up- and download files.
When done, I shut down the ftp server on the phone. Easy-squeezy.