hildon-desktop fails or crashes if it cannot find /dev/mixer device

[AaronL]

Basically, hildon-desktop seems to require that a /dev/mixer device be available--if /dev/mixer does not exist, hildon-desktop encounters an error and either exits or crashes. When this occurs, because hildon-desktop is configured to automatically restart when it exits, it continually restarts and exits or crashes if /dev/mixer is not available. Also, the error is not exactly obvious, but when hildon-desktop is started from the command line, an error is displayed regarding not being able to find a /dev/mixer device. A /dev/mixer device won't exist, for instance, on a Crownbeach SDV, if the HD audio add-in card is not installed (as was the case when the issue occurred).

The expected behavior would be for hildon-desktop not to require /dev/mixer and only use it if the device exists.

[Zhao Fan (fan-zhao)]

We are continuously meeting the hildon-desktop crash issue while doing M6 testing. It even blocks us to run BLTK because the hildon-desktop will crash suddenly. We haven't found a way to stable reproduce the issue, not sure if it is the same issue as this bug describes.

[AaronL (aaron-n-levinson)]

To see what is going on with hildon-desktop, I found that the best approach is to modify /usr/share/ume-config-common/ume-gui-start and change the following line:

exec /usr/bin/hildon-desktop

to something like

exec /usr/bin/xterm

When xterm starts up, run hildon-desktop from the command line--you will then be able to see any errors as they are printed out to the console. There are also various warnings that may be indicative of other issues too.

Zhao: if you have the HD audio card installed, then I doubt that the issue with /dev/mixer is the cause of your problem, but you will see similar results if hildon-desktop crashes or fails. You can use the technique I described above to further isolate the cause of the hildon-desktop failure.

[Horace (horace-li)]

Alek has ever found the same issue that hildon-desktop will crash if no sound card is installed, we will take a look on this. It might be related with moblin-applets volume control on statusbar.

[Bob Spencer (bob-spencer)]

<bspencer> ToddBrandt, 156932: hildon-desktop fails or crashes if it cannot find /dev/mixer device
<ToddBrandt> well, the volume sapplet was what was looking for /dev/mixer, and if it crashes, hildon-desktop crashes
<ToddBrandt> so I changed it to just do nothing if it doesn't find /dev/mixer, it just creates the slider but the slider does nothing, since there's no way to cleanly kill an sapplet in hildon-deskp[
<ToddBrandt> went in on wed of last week, moblin-applets 0.16 I think.
<bspencer> cool. I would rather have it show no slider and when you clicked on the icon it popped up a dialog that said "No sound device present"
<ToddBrandt> we could, but the bug only happens in xephyr, so I thought it would be better to just show the user what the slider would look like if dev/mixer was there
<ToddBrandt> well, I guess it also happens on CB with no soudn card
<ToddBrandt> I can make that change, one moment
<bspencer> ToddBrandt, thanks. That will be somewhat informative at least.

[yanglei (lei-a-yang)]

In the Latest image, we found if no sound card on CB, the Hildon-Desktop will not start up successfully.
The bug reported by Jing (Bug #176032). please check it and see if the both bugs have same root cause.

[cathyli (cathy-li)]

The issue fixed in applets 0.24, close it.