at91sam9: watchdog: period

[Boris Brezillon]

Hi Jiri,

On Fri, 15 May 2015 09:16:37 +0200
Jiří Prchal <jiri.prchal at aksignal.cz> wrote:

> Hi all,
> I'm trying to discover what's wrong with watchdog on my board. I didn't find anything about it on internet so I would 
> ask you for help.
> I have a board with sam9g25 and slow clock xtal 32768Hz with 10p capacitors to GND. Frequency seems to be good since 
> hwclock (RTC) runs pretty precisely powered from backup and main power too (no NTP). But watchdog time to reset is still 
> 61s regardless default (16s) or 4s heartbeat setting. No change to WDT_MR in bootstrap, so in Linux should work.
> Here is dump:
> [    0.000000] Booting Linux on physical CPU 0x0
> [    0.000000] Linux version 4.0.2_cpm9g25 (prchal at prchal) (gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-12ubuntu1) ) #10 
> PREEMPT Thu May 14 15:20:24 CEST 2015
> [    0.000000] CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=0005317f
> [    0.000000] CPU: VIVT data cache, VIVT instruction cache
> [    0.000000] Machine model: AKsignal CDU9G25_v6
> [    0.000000] Memory policy: Data cache writeback
> [    0.000000] AT91: Detected soc type: at91sam9x5
> [    0.000000] AT91: Detected soc subtype: at91sam9g25
> ...
> [    4.669669] AT91: Starting after watchdog reset
> [    4.675675] at91sam9_wdt: enabled (heartbeat=4 sec, nowayout=1)
> ...
> 
> / # killall watchdog
> [ 1821.114114] watchdog watchdog0: nowayout prevents watchdog being stopped!
> / # [ 1821.123123] watchdog watchdog0: watchdog did not stop!
> [ 1882.294294] at91sam9_wdt: I will reset your machine !

Is this file present on your board ?
/proc/device-tree/ahb/apb/watchdog at fffffe40/atmel,idle-halt

If it is then you should patch your DT to remove the property.

Best Regards,

Boris


-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com