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Date:   Wed, 11 Oct 2023 10:49:58 +0200
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Subject: Re: [PATCH v6 10/11] ARM: dts: stm32: add ETZPC as a system bus for
 STM32MP15x boards
To:     Rob Herring <robh@kernel.org>
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References: <20231010125719.784627-1-gatien.chevallier@foss.st.com>
 <20231010125719.784627-11-gatien.chevallier@foss.st.com>
 <20231010184212.GA1221641-robh@kernel.org>
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From:   Gatien CHEVALLIER <gatien.chevallier@foss.st.com>
In-Reply-To: <20231010184212.GA1221641-robh@kernel.org>
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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@foss.st.com>
>> ---
>>
>> 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