Red Hat Bugzilla – Bug 249649
digikam failed to connect to the camera
Last modified: 2007-11-30 17:12:11 EST
Description of problem:
Download of pictures from digital camera no longer works but fails with popup
message "Failed to connect to the camera. Please make sure it is connected
properly and turned on. Would you like to try again?"
Version-Release number of selected component (if applicable):
Steps to Reproduce:
0. login as ordinary user
1. launch digikam from K menu
2. connect and turn on camera
3. select the camera in the list under digiKams main menu option "Camera"
digiKam launches a popup titled "Conenction Failed - digiKam" saying
"Failed to connect to the camera. Please make sure it is connected properly
and turned on. Would you like try again?" with "Retry" and "Abort" as the
possible inputs. Clicking "Retry" relaunches the same popup.
digiKam used to show a panel of thumbnails of the pictures in the camera.
This appears to be a (device) permission issue. Because the issue disappears
if digiKam is launched from the commandline using sudo rather than from the
K-menu as ordinary user. Except that the downloaded pictures are then owned by
yesterday, I had exactly the same problem. I've tried to use the gphoto2 command
line tool to retrieve the photos to get some more debug output - same issue.
strace revealed, that the program could not access the usb-device:
open("/dev/bus/usb", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY) = -1 ENOENT
(No such file or directory)
open("/proc/bus/usb/007/014", O_RDWR) = -1 EACCES (Permission denied)
It looks like, that the access to /prob/bus/usb is some kind of fallback if
/dev/bus/usb is not available.
For some other reason I had to reboot, and after that it just started to work
The difference is, that now /dev/bus/usb is available again, and in this
directory the user had write access:
ls -la /dev/bus/usb/007/010
crw-rw-r--+ 1 root root 189, 777 2007-07-29 17:34 /dev/bus/usb/007/010
getfacl: Removing leading '/' from absolute path names
# file: dev/bus/usb/007/010
# owner: root
# group: root
Sure, the question is now: Why was /dev/bus/usb not available when the problem
My assumption is, that during the various regular updates of Fedora 7 (without
any reboots) for whatever reason /dev/bus/usb vanished (probably hal/udev
update, kernel update or something like this).
Claus, please can you try first, whether a reboot helps?
- use lsusb to figure out at which usb port your camera is connected
- check the permissions of the according /dev/bus/usb/aaa/bbb entry with "ls -l"
- try using gphoto2 with "strace -eopen -o /tmp/gphoto2trace gphoto2 -l" and
check, whether the usb device files can be accessed
Hope that helps.
Thank you for your comment and hints. I just retested and the problem has now
vanished - on its own. I'll close this bug report if I can.
Since posting then according to
$ rpm -qa --dump --last
I have gotten the following updates
kernel-headers-220.127.116.11-33.fc7 Fri 27 Jul 2007 05:40:06 PM PDT
bind-utils-9.4.1-8.P1.fc7 Fri 27 Jul 2007 05:40:05 PM PDT
kmod-nvidia-100.14.11-18.104.22.168.1_33.fc7 Fri 27 Jul 2007 05:40:03 PM PDT
kernel-devel-22.214.171.124-33.fc7 Fri 27 Jul 2007 05:39:55 PM PDT
kernel-126.96.36.199-33.fc7 Fri 27 Jul 2007 05:37:43 PM PDT
bind-libs-9.4.1-8.P1.fc7 Fri 27 Jul 2007 05:37:25 PM PDT
adobe-release-i386-1.0-1 Thu 26 Jul 2007 05:30:29 PM PDT
Might the kernel update have fixed this? The changelog for the kernel update
$ rpm -q --changelog kernel-188.8.131.52-33.fc7
The computer is turned off when not in use i.e. at least every night. On the
day of posting I got these updates
libXi-devel-1.1.1-1.fc7 Wed 25 Jul 2007 06:26:27 PM PDT
kde-settings-kdm-3.5-30.fc7 Wed 25 Jul 2007 06:26:26 PM PDT
kde-settings-3.5-30.fc7 Wed 25 Jul 2007 06:26:25 PM PDT
ntfs-3g-1.710-1.fc7 Wed 25 Jul 2007 06:26:24 PM PDT
anthy-9100-1.fc7 Wed 25 Jul 2007 06:26:07 PM PDT
kdesdk-3.5.7-7.fc7 Wed 25 Jul 2007 06:25:46 PM PDT
evolution-data-server-184.108.40.206-2.fc7 Wed 25 Jul 2007 06:25:39 PM PDT
fuse-2.7.0-3.fc7 Wed 25 Jul 2007 06:25:36 PM PDT
libXi-1.1.1-1.fc7 Wed 25 Jul 2007 06:25:35 PM PDT
fuse-libs-2.7.0-3.fc7 Wed 25 Jul 2007 06:25:13 PM PDT
but can't remember if I rebooted after that update before using digiKam.
Besides, none of those ring a bell with me as candidates for being able to
make a difference.
I've retested all USB ports with all other USB devices plugged-in and -out -
and can't make the problem reappear. That is without going to extremes. I can
make the problem happen by this sequence
1. Cancel the KDE popup that shows when the camera is turned on.
2. Right click the KDE Desktop digiKam icon and select "digiKam Detect and
3. Quickly dismiss the digiKam popup window by clicking "X" in the window
border or using KDEs Alt-F4 before digiKam starts downloading from the camera.
4. repeat from step 2 (without closing digiKam) and digiKam shows the "Failed
to connect to the camera..." popup but only until after some clicks on
the "Retry" button after which digiKam starts downloading from the camera and
everything is fine.
This is a constructed and extreme case and not a bug. My point with mentioning
this is that a usb device permission issue is not the only possible candidate
as cause of the problem.
I don't know if SELinux could be the cause but if so then it shouldn't be
because I have never had it enabled.
At this point I'm at a loss on how to explain why it now works again.
The tools tip popup as well as the right click Properties->Meta Info of the
KDE Desktop camera icon says
Base URL: camera://USB PTP Class Camera@[usb:002,008]/
ls -l /dev/bus/usb/002/008
crw-rw-r--+ 1 root root 189, 135 2007-07-29 11:01 /dev/bus/usb/002/008
Perhaps that last line read
crw-------+ 1 root root ...
at the time of the problem. I'll check for that if the problem should happen