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November 24, 2025
Question

STM32MP135A Needs An LSE? (meta-st-stm32mp)

  • November 24, 2025
  • 1 reply
  • 122 views

So coincidental enough all the projects I have done before required a RTC /w LSE. I am now working on a project that does not need a LSE, and I am finding that TF-A keeps throwing a panic because of this. The protos we had fortunately had the circuit DNL, so adding an LSE clock fixed the problem. 

Is there a way to disable this? or at least use the LSI? I tried configuring it to use the LSI but still same panic. 
//Error Message

NOTICE: Early console setup
PANIC at PC : 0x2ffe6b5b

Exception mode=0x00000016 at: 0x2ffe6b5b



Thank you for any help. 


    This topic has been closed for replies.

    1 reply

    Technical Moderator
    December 2, 2025

    Hello @ChrisRCAL 

     

    Thank you for this, we have identify an issue in the OSTL DV6.1. A patch is available to deactivate the external oscillator when not available and prevent panic, but its frequency needs to be set to 0 in the DT. The following patch will be implemented in the next DV. Let us know if it fixes your issue.

     

     

    stm32mp-openstlinux-6.6-yocto-scarthgap-mpu-v25.08.27/sources/ostl-linux/tf-a-stm32mp-v2.10.13-stm32mp-r2-r0/tf-a-stm32mp-v2.10.13-stm32mp-r2/drivers/st/clk/clk-stm32mp2.c

     

    diff --git a/drivers/st/clk/clk-stm32mp2.c b/drivers/st/clk/clk-stm32mp2.c

    index 9c93db5..6552161 100644

    ---    a/drivers/st/clk/clk-stm32mp2.c

    +++ b/drivers/st/clk/clk-stm32mp2.c

    @@ -846,6 +846,10 @@

     {

      struct clk_oscillator_data *osc_data = clk_oscillator_get_data(priv, id);

    + if (osc_data->frequency == 0UL) {

    + return true;

    + }

    +

      return _clk_stm32_gate_is_enabled(priv, osc_data->gate_id); }