Unblacklisting the ARM SBSA Watchdog driver

[Timo Aaltonen]

Hi Antoine,

Could you file a bug so you can track this change and also leaves a more 
permanent trail for us.

On 22.1.2026 9.41, Antoine Lassagne wrote:
> Hi Paolo,
> 
> Thank you, that's great news. A few follow-up questions:
> - Is there a way for me to test this already? Maybe I can simply build 
> the unstable branch locally?
> - When is 6.19 due in resolute/linux?
> I'll run some verifications on it, and will also try to get it verified 
> against more arm64 machines. Thank you again.
> 
> Antoine
> 
> On Wed, 21 Jan 2026 at 17:16, Paolo Pisati <paolo.pisati at canonical.com 
> <mailto:paolo.pisati at canonical.com>> wrote:
> 
>     On Thu, Jan 15, 2026 at 4:04 PM Antoine Lassagne
>     <antoine.lassagne at canonical.com
>     <mailto:antoine.lassagne at canonical.com>> wrote:
> 
>         Hello kernel team,
> 
>         I'm asking here about the possibility of removing the blacklist
>         that is put on the sbsa_gwdt module.
>         This module handles the ARM SBSA Generic watchdog [1]. The
>         module kicks the watchdog when it's there and, without it, some
>         machines will get unattended reboot after a few minutes of uptime.
> 
>         All the watchdog modules were blacklisted a long time ago, after
>         there were problems with an HP watchdog if I understand it
>         correctly. This comment from Andy Whitcroft [2] is the closest
>         related message I could find about "why" this blacklist exists.
> 
>         Now, some devices actually need this. Lately, Nvidia released
>         ARM devices that are based on an Ubuntu-based distro [3]. But if
>         someone wants to install stock Ubuntu on these, the hardware
>         will reboot after 10min.
> 
>         After I asked around, I came up with a hacky package that
>         bypasses the blacklist only on some identified hardware [4]. The
>         problem is that it requires us to identify the hardware first,
>         and then it's hard-coded and will not support new hardware
>         without an update. Unblacklisting the watchdog would be very,
>         very much better, so much more hardware would be supported.
> 
>         Is there a path towards unblacklisting this specific watchdog
>         on  resolute/devel, and get some user feedback?
> 
> 
>     Hi Antoine,
>     your request makes sense: i pushed a patch on top of linux-unstable
>     [1] that removes sbsa_gwdt from the watchdog blacklist - it will
>     appear in resolute/linux once it moves to v6.19.
> 
>     1: https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/
>     +git/unstable <https://git.launchpad.net/~ubuntu-kernel/ubuntu/
>     +source/linux/+git/unstable>
>     -- 
>     bye,
>     p.
> 
> 


-- 
Timo Aaltonen
Kernel Team
Canonical Ltd.