[App_rpt-users] Watchdog timer in Pickle linux (remove omap_wdt?)

[Mike Hugo]

After sending my email to this group last week, I got a chance to dive
deeper into the watchdog timer of the beagleboard and got it to work on the
rev C XM board. The solution is fairly simple and I figured I would
document it here as others might be interested.  With this config change
the board will reboot itself if it detects certain conditions. This is
reported to work for all versions of the beagleboard.  Only time will tell
if this will prevent a trip to a mountaintop but it should hopefully solve
the problem we encountered with a hung reboot.

Since Jim included a full build environment in pickle Linux,  it is easy to
rebuild the kernel in place.   The steps to change the watchdog timer from
the default of omap_wdt to twl4030 are simple. Unlike what I said in my
original email the default kernel only has the omap_wdt timer.

The steps are (some of these are probably unnecessary) :
cd /usr/src/linux
make menuconfig
  (navigate to the drivers/watchdog and remove the star next to the
omap_wdt and put a star next to the twl4030_wdt)
make
make modules
make uImage
make modules_install
make install
cp /boot/uImage /boot/uImage_orig
cp arch/arm/boot/uImage /boot/uImage
reboot

After the reboot   "cat /dev/watchdog" and the board should reboot after
about 30 seconds.  Assuming the board reboots and doesn't hang then the
watchdog user space app can be added. To install it run "apt-get install
watchdog" and then configure the /etc/watchdog.conf file.  At a minimum
remove the comment on the /dev/watchdog line but you can also configure it
to check all sort of other parameters.  By default it will start when the
board is started.

Mike




On Thu, Nov 7, 2013 at 9:28 AM, Mike Hugo <ka6oij at arrl.net> wrote:

> Hi,
>
> A bit of investigation with Dr. Google found that the beagleboard XM
> boards have a known issue with the omap_wdt driver. Instead of rebooting
> the board it holds it in reset.  The easy solution is to not use the
> omap_wdt watchdog timer driver but rather the TLW4030 watchdog timer driver.
>
...

>
> A quick way to test the watchdog timer is to just cat /dev/watchdog and
> wait a minute. Current XM boards with the omap_wdt timer will crash after a
> minute.  Newer beagleboards will restart. If my theory is correct after
> removing the omap_wdt driver all boards will restart
>
>
> Thanks
> Mike
>
>
> Here is reference where someone did the research on the watchdog timer:
> http://gumstix.8.x6.nabble.com/Watchdog-timer-not-working-in-gumstix-overo-td812498.html
> Look near the bottom with the solution.
> I also saw references on the TI site and perhaps the omap_wdt driver has
> been updated as well since these posts are old.
>
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