From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Fri, 15 May 2015 17:25:16 +0200 Subject: at91sam9: watchdog: period In-Reply-To: <55559D55.6020703@aksignal.cz> References: <55559D55.6020703@aksignal.cz> Message-ID: <20150515172516.005e3a21@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Jiri, On Fri, 15 May 2015 09:16:37 +0200 Ji?? Prchal 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