[maemo-developers] Continuous reboot problem with the N770 hacker edition

[From: Daniel Stone]

On Thu, Apr 26, 2007 at 06:56:40PM +0300, ext Eero Tamminen wrote:
> Hi,
> 
> > I still think this watchdog thing is another legacy we have from Nokia
> > as a phone company. It makes perfect sense for dumb phone. It makes less
> >   sense for computer. Yes when device locks up you need a way to reset
> > it. That is why you have reset button on computer and also reset hole on
> > every PDA. I know it is internet tablet not computer or PDA but also
> > Nokia should know that *this is not a phone* ;-)

Anything with a radio (of which has the N800 has two) gets a watchdog.
Honestly, I don't think this is particularly insane.

> > With reset hole one can reset device when (s)he wants. Watchdog may not
> > make things worse when device locks up solid (i.e. kernel bug or
> > feature) but rebooting device when some process dies of when things take
> > too long can make more damage than benefit. I know this is hard to
> > detect so my solution is to provide reset hole and do not try to guess.
> > User probably can notice this situation and act accordingly.
> 
> This is improved a bit in latest release.  Most things are restartable
> and device is rebooted only if restarting them fails too many times in
> a row (Desktop, window manager etc).
> 
> However, without X server or D-BUS you cannot use the device at all
> and all your UI processes exit automatically, so it doesn't make sense
> to try to "keep the device up" if those exit/crash.

The sensible solution is to pull the desktop down and restart it along
with the X server, instead of panicking and rebooting the device.
Unfortunately, our init system (osso-af-init) is so horribly designed
that it's almost impossible to do[0] without just blowing away our init
system and starting again _from scratch_.  Which is arguably what we
should do, anyway.

Cheers,
Daniel

[0]: I had an ndm for exactly this internally, but due to the init
     scripts being so incredibly broken both by horrible design and
     awful implementation, the init scripts always returned failure,
     even if they succeeded.  Go figure.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : http://lists.maemo.org/pipermail/maemo-developers/attachments/20070426/c413e3a9/attachment.pgp