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

From: Gatien CHEVALLIER
Date: Wed Oct 11 2023 - 04:51:13 EST


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