OK, I found something buried in a Kconfig:
https://elixir.bootlin.com/linux/v5.10/source/drivers/watchdog/Kconfig#L268
wdat_wdt maybe replaced iTCO_wdt:
This driver adds support for systems with ACPI
<https://elixir.bootlin.com/linux/v5.10/K/ident/CONFIG_ACPI> Watchdog
Action Table (WDAT) table. Servers typically have this but it can
be found on some desktop machines as well. This driver will take
over the native iTCO watchdog driver found on many Intel CPUs.
Indeed I tried out the wdat_wdt and it works, so maybe that is the intended
way. I suppose this is now not really a Debian-specific thing, so I will
maybe try the kernel mailing list.
Thanks!
Perry
On Wed, Mar 8, 2023 at 12:34 PM Perry Naseck <[email protected]>
wrote:
> OK, I looked at the source for this module:
> https://github.com/torvalds/linux/blob/master/drivers/watchdog/iTCO_wdt.c
>
> Unless the latest version has changed drastically from 5.10.0-21, then I
> should be seeing an error of some sort if it is running the probe function
> iTCO_wdt_probe(). Every return in that function before "Found a %s TCO
> device" is an error. What would cause the probe not to run at all?
>
> Also, I tried disabling secure boot to no avail.
>
> Thanks,
> Perry
>
> On Wed, Mar 8, 2023 at 11:00 AM Perry Naseck <[email protected]>
> wrote:
>
>> Hello!
>>
>> I cannot get the iTCO_wdt device to be found. I'm not sure how else to
>> troubleshoot at this point, so any help with that is appreciated (i.e. a
>> way to manually check if the device exists or etc.).
>>
>> I am using Debian 11 on an Intel NUC CMCR1ABB chassis with a CM11EBi716W
>> module. This is an i7 and the watchdog is enabled in the BIOS. I am using
>> the latest BIOS v71. Kernel: 5.10.0-21-amd64 #1 SMP Debian 5.10.162-1
>> (2023-01-21) x86_64 GNU/Linux.
>>
>> Every single time I run "modprobe iTCO-wdt" I see in dmesg:
>> iTCO_vendor_support: vendor-support=0
>> iTCO_wdt: Intel TCO WatchDog Timer Driver v1.11
>> And that's it. No device found and no new /dev/watchdog devices or
>> anything new in wdctl.
>>
>> I have tried:
>> 1. Simply "modprobe iTCO-wdt"
>> 2. Also loading "i2c-i801" and "i2c-smbus" first and then loading the
>> module
>> 3. Blacklisting wdat_wdt and adding nmi_watchdog=0 to GRUB, which
>> correctly caused the existing /dev/watchdog software device to disappear
>> but iTCO_wdt still didn't work
>>
>> I found one other user with the same issue several years go:
>> https://forums.debian.net/viewtopic.php?t=146358
>>
>> I'm very certain that this device supports the watchdog, as there is a
>> BIOS option to enable it and Intel has a Windows daemon to make use of it.
>> Is there another Intel watchdog scheme besides iTCO_wdt? Would secureboot
>> lockdown be interfering with this?
>>
>> Thanks,
>> Perry
>>
>
