Unexpected reboot after cold start-up or wake-from-suspend with watchdogd enabled

[Dan-Lightsource]

When the watchdogd (watchdog timer daemon) service is enabled on an AAEON PICO-APL3 board running this BSP, the board may reboot suddenly during start-up after a cold boot. Similarly, if waking from suspend (e.g. using Wake-on-LAN), the board may also reboot.

[Dan-Lightsource]

The problem was root-caused as a bug in the 'ec_wdt' watchdog kernel device driver for the WDT used on the PICO-APL3 (and some other PICO boards in the range).

The problem is that the WDT configuration register is not properly initialised and so, after start-up, it contains an incorrect power-on default configuration which sets the wrong polarity for the WDT alarm output signal and thus causes an immediate reset when enabled.

Patches are attached to address the issue, and also for some minor cosmetic clean-up of unnecessary log messages from the driver: pico-apl3_wdt-patches.zip