kernel log "/cpus/cpu@0 missing clock-frequency property" on stm32mp151C

[JSand.10]

We are running a stm32mp151c with stm32mp linux built with yocto.

The kernel complain that the cpu0 clocl-frequency is not set, but the patch

layers/meta-st/meta-st-stm32mp/recipes-kernel/linux/linux-stm32mp/5.10/5.10.116/0022-ARM-5.10.116-stm32mp1-r2.1-DEVICETREE.patch removes DTS clock-freuency setting

line 3889: -         clock-frequency = <650000000>;

From release notes STM32 MPU OpenSTLinux release note - v4.0.0 - stm32mpu for 5.15 I found "BL2 always boots at 650MHz" and it seems the kernel should probe for cpu clock-frequency. The board boots, but we get these log entries that makes me wonder if we miss anything in DTS:

"Starting kernel ...

[  0.003140] /cpus/cpu@0 missing clock-frequency property

[  2.666366] stm32-cpufreq stm32-cpufreq: Failed to get chip info: -517"

Could anyone give me a hint where I can find more info about this patch and the background for removing the DTS cfg line "clock-frequency = <650000000>" but still code want to find DTS cfg please? I understand the opp should replace this but can both be used at the same time?

[Olivier GALLIEN]

Hi @Johan Sandström​ ,

I understand you are in kernel 5.10 / V3.x ... Pay attention to refer to the relevant wiki

stm32mpu-ecosystem-v3

Anyway the traces you report are simple warning that can be ignore in this version.

They are removed in V4.x / kernel 5.15

Hope it help,

Olivier

[JSand.10]

Thanks a lot! I will look at the patches for 4.X .

[debugging]

These are traces in 6.1

[ 0.000000] OF: fdt: Machine model: STMicroelectronics custom STM32CubeMX board - openstlinux-6.1-yocto-mickledore-mp1-v23.06.21
[ 0.000000] printk: bootconsole [earlycon0] enabled
[ 0.003370] /cpus/cpu@0 missing clock-frequency property
[ 0.008773] /cpus/cpu@1 missing clock-frequency property

[debugging]

This warning went away by adding the cpu frequency in the DTS.  (ECO 5.0. , kernel 6.1). CubeMX did NOT add those.