But you have to delete hw_watchdog_init(). If you set there MR then linux won't be able to do it. The patch needs only the WATCHDOG_RESET() and nothing more.
I agree.
you need to update linux, the watchdog can be enable in u-boot but as it can only be disable once if u-boot or any other bootloader init we can not disable it so in this case linux will just have to buy time to the watchdog
On the sam926x processors It can only be confitured once. So Giulio is right: u-boot shouldn't configure it, just kick it any now and then.
When a client asked to used the watchdog on the 9260 I chose not to disable it in at91boot nor in u-boot. Then Linux (i.e., the final user) could do whatever was fit: either disable it, enable it with a faster timeout or leave it alone (at 13s or whatever the default is) until some application sets a policy.
I don't like this hardware choice of "configure once only": never-disable makes sense, but never-enable doesn't, in my opinion. But based on that the right thing for u-boot is not configuring it a all, or we loose flexibility in later stages.
/alessandro