Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.user > #255706 > unrolled thread

iTCO_wdt not finding device

Back to article view | Back to linux.debian.user

Contents

  iTCO_wdt not finding device Perry Naseck <mailinglists@perrynaseck.com> - 2023-03-08 17:20 +0100
    Re: iTCO_wdt not finding device Perry Naseck <mailinglists@perrynaseck.com> - 2023-03-08 19:00 +0100
      Re: iTCO_wdt not finding device Perry Naseck <mailinglists@perrynaseck.com> - 2023-03-08 21:30 +0100
        Re: iTCO_wdt not finding device Perry Naseck <mailinglists@perrynaseck.com> - 2023-03-09 04:10 +0100

#255706 — iTCO_wdt not finding device

[Multipart message — attachments visible in raw view] — view raw

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

[toc] | [next] | [standalone]

#255708

[Multipart message — attachments visible in raw view] — view raw

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 <mailinglists@perrynaseck.com>
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
>

[toc] | [prev] | [next] | [standalone]

#255709

[Multipart message — attachments visible in raw view] — view raw

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 <mailinglists@perrynaseck.com>
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 <mailinglists@perrynaseck.com>
> 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
>>
>

[toc] | [prev] | [next] | [standalone]

#255712

[Multipart message — attachments visible in raw view] — view raw

One final followup for completeness for anyone running into this issue who
may find this thread via search: Yes, wdat_wdt effectively replaces
iTCO_wdt.

The kernel patch puts it pretty simply: https://lwn.net/Articles/700524/

WDAT is a watchdog timer abstraction that is a much more
hardware-independent API (assuming the manufacturer implements it). iTCO
will simply not create a watchdog if WDAT is available (probably even if
wdat_wdt is not loaded).

In fact, there is a good chance that iTCO would never have worked on my
device because Intel changed the exact method/bus location of accessing it
on newer CPUs. This change may not have been implemented in the iTCO kernel
driver because WDAT is now common and iTCO would only be needed on systems
that it already works with.

NOTE: All of the above info is from that patch message text; I did not look
at any code to confirm exact functionality of how the iTCO ignores/loads,
but this completely matches the behavior of my system.

Best,
Perry

On Wed, Mar 8, 2023 at 3:11 PM Perry Naseck <mailinglists@perrynaseck.com>
wrote:

> 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 <mailinglists@perrynaseck.com>
> 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 <
>> mailinglists@perrynaseck.com> 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
>>>
>>

[toc] | [prev] | [standalone]

Back to top | Article view | linux.debian.user

csiph-web