The issue of using discrete power supply in STM32MP157D

[zengyixiang]

The power supply part of the board I made myself did not use "stpmic", but used a discrete power supply. I encountered an issue when porting OpenSTLinux (5.1.0). After modifying the power supply in the "u boot" device tree and using "STM32CubeProgrammer" to download, it kept downloading repeatedly, as shown in the following figure:

I have modified these positions: under "i2c4", the "pmic: stpmic@33 All nodes have been deleted, and the following content has been added to the root node:

vddcore: regulator-vddcore {

        compatible = "regulator-fixed";

regulator-name = "vddcore";

regulator-min-microvolt = <1200000>;

regulator-max-microvolt = <1350000>;

regulator-always-on;

        regulator-boot-on;

};

    v3v3: regulator-3p3v {

        compatible = "regulator-fixed";

        regulator-name = "v3v3";

        regulator-min-microvolt = <3300000>;

        regulator-max-microvolt = <3300000>;

        regulator-always-on;

        regulator-boot-on;

    };

    v1v8_audio: regulator-v1v8-audio {

        compatible = "regulator-fixed";

        regulator-name = "v1v8_audio";

        regulator-min-microvolt = <1800000>;

        regulator-max-microvolt = <1800000>;

        regulator-always-on;

        regulator-boot-on;

    };

    vdd: regulator-vdd {

        compatible = "regulator-fixed";

        regulator-name = "vdd";

        regulator-min-microvolt = <3300000>;

        regulator-max-microvolt = <3300000>;

        regulator-always-on;

        regulator-boot-on;

    };

    vdd_usb: regulator-vdd-usb {

        compatible = "regulator-fixed";

        regulator-name = "vdd_usb";

        regulator-min-microvolt = <3300000>;

        regulator-max-microvolt = <3300000>;

        regulator-always-on;

        regulator-boot-on;

    };

[zengyixiang]

Has anyone encountered this situation before? How should we solve it

[zengyixiang]

Is anybody there

[PatrickF]

Hi @zengyixiang 

Hard to solve your issue with few informations.

Maybe linked to DDR issue which mean uBoot crash at some point of time (use STM32DDRFW-UTIL to confirm behavior) . Maybe issue with mixed-up DDR signals (e.g. DQS or DM mixed with DQ bytes lanes) which create trouble as soon as non-32-bits data are needed from DDR.

Any HW issue which could generate a reset (e.g. supply drop, conflicts on signals, etc...) ?

Any memory size issue (i.e. UBoot or else trying to use unavailable DDR memory which could corrupt some other DDR area due to mirroring) ?

Regards.

[zengyixiang]

Thank you, I have identified the issue

[PatrickF · Accepted solution]

Hi @zengyixiang 

nice to see you solved the issue.

Could you share the solution as it could be of interest of other members of the forum who fall into similar issue?

Regards.

[zengyixiang]

There is a power supply issue with my board