Re: [RFC PATCH] arm64: dts: ls1028a: mark ARM SMMU as DMA coherent

[Vladimir Oltean]

On Tue, Jan 03, 2023 at 06:12:29PM +0000, Robin Murphy wrote:
> > I have a side question, why is the dev_name() of your SMMU set to
> > "arm-smmu.0.auto" (determined by PLATFORM_DEVID_AUTO if I'm not mistaken)?
> 
> This is an ACPI-based machine, where platform device discovery and creation
> is... different :)
> 
> SMMUs are among those managed by drivers/acpi/arm64/iort.c
> 
> > I'm asking because I would like to study the mechanism through which
> > your SMMU platform device get probed, to make sure that it's not
> > possible, during shutdown, for both platform_driver :: shutdown()
> > and platform_driver :: remove() methods to get called by the driver core.
> > This is generally not disallowed, and even possible if the entity who
> > registers these platform devices has its ->shutdown() method pointing
> > at ->remove().
> 
> Yikes, I'd very much hope that that's not a thing!

Ah, ok. Appears to be fine. Looking at drivers/acpi/arm64/iort.c,
it seems that no one is removing those platform devices.