Re: watchdog: iTCO_wdt: failed to load

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Vignesh Raman <vignesh.raman.in@gmail.com>,
	mika.westerberg@linux.intel.com
Cc: linux-watchdog@vger.kernel.org, rajneesh.bhardwaj@linux.intel.com
Subject: Re: watchdog: iTCO_wdt: failed to load
Date: Wed, 24 Jul 2019 19:06:01 +0300	[thread overview]
Message-ID: <20190724160601.GA9224@smile.fi.intel.com> (raw)
In-Reply-To: <CAH3OF53GqY-h+9woZS_8Kx671PCiCFjVbaFQ_gs30ZXMWxUO8g@mail.gmail.com>

+Cc: Mika, who is supporting watchdog driver(s).

On Wed, Jul 24, 2019 at 01:04:45PM +0530, Vignesh Raman wrote:
> Hi,
> 
> I'm seeing an issue where the iTCO_wdt module doesn't load with the below error,
> 
> [    3.827599] iTCO_wdt: Intel TCO WatchDog Timer Driver v1.11
> [    3.828440] iTCO_wdt iTCO_wdt: can't request region for resource
> [mem 0x00c5fffc-0x00c5ffff]
> [    3.828803] iTCO_wdt: probe of iTCO_wdt failed with error -16
> 
> CPU and logs:
> cpu: Intel(R) Core(TM) i3-8100 CPU @ 3.60GHz
> dmesg logs: http://paste.debian.net/1092702/
> lsmod output: https://paste.debian.net/1092703/
> root@localhost:~# uname -a
> Linux localhost.localdomain 4.14.103-rt55 #1 SMP PREEMPT RT Tue Jul 23
> 03:53:28 UTC 2019 x86_64 GNU/Linux
> 
> Please let me know if the error (can't request region for resource) is
> related to the patches below,
> https://patchwork.kernel.org/patch/9627085/
> https://lore.kernel.org/patchwork/patch/770990/
> 
> I tested with the patch
> https://lore.kernel.org/patchwork/patch/770990/ and it fixes the
> issue.
> root@localhost:/home/vignesh# dmesg | grep wdt
> [    5.766470] iTCO_wdt: Intel TCO WatchDog Timer Driver v1.11
> [    5.767104] iTCO_wdt: Found a Intel PCH TCO device (Version=4,
> TCOBASE=0x0400)
> [    5.767865] iTCO_wdt: initialized. heartbeat=30 sec (nowayout=0)
> 
> But the patch was not merged upstream.
> 
> When testing the hardware watchdog, it doesn't trigger a reset even
> after triggering a sysrq crash.
> The system freezes and there is no reboot.
> 
> I noticed the timeleft value is not getting updated.
> root@localhost:~# cat /sys/class/watchdog/watchdog0/timeleft
> 15
> root@localhost:~# cat /sys/class/watchdog/watchdog0/timeleft
> 15
> root@localhost:~# cat /sys/class/watchdog/watchdog0/timeleft
> 15
> 
> This issue has been discussed in below email thread,
> http://lkml.iu.edu/hypermail/linux/kernel/1609.1/01979.html
> https://lkml.org/lkml/2016/9/8/641
> 
> In another platform the hardware watchdog works.
> root@debian:~# dmesg | grep wdt
> [    3.901842] iTCO_wdt: Intel TCO WatchDog Timer Driver v1.11
> [    3.903415] iTCO_wdt: Found a Intel PCH TCO device (Version=4,
> TCOBASE=0x0400)
> [    3.937816] iTCO_wdt: initialized. heartbeat=30 sec (nowayout=0)
> 
> CPU and logs
> cpu: Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz
> dmesg logs: http://paste.debian.net/1092845/
> lsmod output: http://paste.debian.net/1092846/
> root@debian:~# uname -a
> Linux debian 4.14.103-rt55 #1 SMP PREEMPT RT Tue Jul 23 03:53:28 UTC
> 2019 x86_64 GNU/Linux
> 
> Hardware watchdog triggers a reset and the watchdog timer counter is
> started and the value gets updated.
> root@debian:~# cat /sys/class/watchdog/watchdog0/timeleft
> 13
> root@debian:~# cat /sys/class/watchdog/watchdog0/timeleft
> 12
> root@debian:~# cat /sys/class/watchdog/watchdog0/timeleft
> 11
> root@debian:~#
> 
> My questions:
> 1. Please let me know if it is okay to take
> https://lore.kernel.org/patchwork/patch/770990/ patch or will there be
> an update to the original patch?
> 2. Could the hardware watchdog not triggering a reset (timeleft value
> not getting updated) could be a hardware problem?
> 
> Thanks.
> 
> Regards,
> Vignesh

-- 
With Best Regards,
Andy Shevchenko