Re: [PATCH] gpu: nova-core: fb: make sure to unregister SysmemFlush on boot failure

[Danilo Krummrich]

On Mon Apr 13, 2026 at 3:33 PM CEST, Eliot Courtney wrote:
> Yeah, I agree that this patch is the wrong long term solution. If we
> don't have the infra for the proper way to do it soon, it might be worth
> taking it anyway since it adds minimal complexity and fixes a real
> issue.

Yeah, let's see how it goes the next weeks.

> I had a brief look into the Devres chain stuff that exists on the C side
> and it looks like it doesn't provide any actual guarantees about the
> lifetime (it seems possible to delete from the middle of the chain, so
> descendants can't assume ancestors exist in general, AFAICT), so the
> the translation of that into lifetimes in rust might get interesting

There is no such API that does what we want here on the C side. In C it simply
is the responsibility of drivers to take care of this. So, I'm not sure what you
are referring to.

In case you are talking about devres groups, they have a different purpose. They
are used in cases where you e.g. have some middle layer API between drivers and
a subsystem, so the middle layer can acquire resources on the driver's behalf
and manage them. If the middle layer fails on optional features, it can simply
release the group of resources acquired for the purpose of the optional feature.

I.e. devres groups are simply markers for a certain range within the list of
devres nodes of a specific device.