Re: [PATCH v6 10/11] ARM: dts: stm32: add ETZPC as a system bus for STM32MP15x boards

[Gatien CHEVALLIER]

Hi Rob,

On 10/10/23 20:42, Rob Herring wrote:
> On Tue, Oct 10, 2023 at 02:57:18PM +0200, Gatien Chevallier wrote:
> > ETZPC is a firewall controller. Put all peripherals filtered by the
> > ETZPC as ETZPC subnodes and reference ETZPC as an
> > access-control-provider.
> >
> > For more information on which peripheral is securable or supports MCU
> > isolation, please read the STM32MP15 reference manual.
> >
> > Signed-off-by: Gatien Chevallier <gatien.chevallier@xxxxxxxxxxx>
> > ---
> >
> > Changes in V6:
> >      	- Renamed access-controller to access-controllers
> >      	- Removal of access-control-provider property
> >
> > Changes in V5:
> >      	- Renamed feature-domain* to access-control*
> >
> >   arch/arm/boot/dts/st/stm32mp151.dtsi  | 2756 +++++++++++++------------
> >   arch/arm/boot/dts/st/stm32mp153.dtsi  |   52 +-
> >   arch/arm/boot/dts/st/stm32mp15xc.dtsi |   19 +-
> >   3 files changed, 1450 insertions(+), 1377 deletions(-)
>
> This is not reviewable. Change the indentation and any non-functional
> change in one patch and then actual changes in another.

Ok, I'll make it easier to read.

> This is also an ABI break. Though I'm not sure it's avoidable. All the
> devices below the ETZPC node won't probe on existing kernel. A
> simple-bus fallback for ETZPC node should solve that.

I had one issue when trying with a simple-bus fallback that was the
drivers were probing even though the access rights aren't correct.
Hence the removal of the simple-bus compatible in the STM32MP25 patch.

Even though a node is tagged with the OF_POPULATED flag when checking
the access rights with the firewall controller, it seems that when
simple-bus is probing, there's no check of this flag.

of_platform_populate() checks and sets the OF_POPULATED_BUS flag.
Maybe that is my error and the firewall bus populate should set
OF_POPULATED_BUS instead of OF_POPULATED. Is that correct?

Best regards,
Gatien

> Rob