Messages in this thread | | | Subject | Re: [PATCH v2 00/14] Introduce STM32MP1 RCC in secured mode | From | Marek Vasut <> | Date | Thu, 11 Mar 2021 12:43:04 +0100 |
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On 3/11/21 9:08 AM, Alexandre TORGUE wrote: > Hi ALex
Hello everyone,
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>> Subject: Re: [PATCH v2 00/14] Introduce STM32MP1 RCC in secured mode >> >> On 1/26/21 3:01 AM, gabriel.fernandez@foss.st.com wrote: >>> From: Gabriel Fernandez <gabriel.fernandez@foss.st.com> >>> >>> Platform STM32MP1 can be used in configuration where some clocks and >>> IP resets can relate as secure resources. >>> These resources are moved from a RCC clock/reset handle to a SCMI >>> clock/reset_domain handle. >>> >>> The RCC clock driver is now dependent of the SCMI driver, then we have >>> to manage now the probe defering. >>> >>> v1 -> v2: >>> - fix yamllint warnings. >> >> Hi Gabriel, >> >> I don't have much clout with the maintainers, but I have to NAK this series >> after finding major breakage. >> >> The problem with series is that it breaks pretty much every board it touches. >> I have a DK2 here that I'm using for development, which no longer boots with >> this series applied. >> >> The crux of the matter is that this series assumes all boards will boot with an >> FSBL that implements a very specific SCMI clock tree. This is major ABI >> breakage for anyone not using TF-A as the first stage bootloader. Anyone >> using u-boot SPL is screwed. >> >> This series imposes a SOC-wide change via the dtsi files. So even boards that >> you don't intend to convert to SCMI will get broken this way. >> Adding a -no-scmi file that isn't used anywhere doesn't help things. > > You are right. We mainly take care about NO ST (DH/...) boards, but not really about current usage > Of our stm32 boards. Several options exist:
Since a lot of people benefit from the good upstream support for the MP1 _and_ keep updating their machines to get the latest fixes, it is very important to keep the current usage working.
> 1- Break the current ABI: as soon as those patches are merged, stm32mp157c-dk2.dtb will impose to use > A tf-a for scmi clocks. For people using u-boot spl, the will have to create their own "no-secure" devicetree.
NAK, this breaks existing boards and existing setups, e.g. DK2 that does not use ATF.
> 2-As you suggest, create a new "secure" dtb per boards (Not my wish for maintenance perspectives).
I agree with Alex (G) that the "secure" option should be opt-in. That way existing setups remain working and no extra requirements are imposed on MP1 users. Esp. since as far as I understand this, the "secure" part isn't really about security, but rather about moving clock configuration from Linux to some firmware blob.
> 3- Keep kernel device tree as they are and applied this secure layer (scmi clocks phandle) thanks to dtbo in > U-boot.
Is this really better than #include "stm32mp15xx-enable-secure-stuff.dtsi" in a board DT ? Because that is how I imagine the opt-in "secure" option could work.
> The third could be the less costly.
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