2021-07-01 14:04:50

by H. Nikolaus Schaller

[permalink] [raw]
Subject: [PATCH v2] omap5-board-common: remove not physically existing vdds_1v8_main fixed-regulator

This device tree include file describes a fixed-regulator
connecting smps7_reg output (1.8V) to some 1.8V rail and
consumers (vdds_1v8_main).

This regulator does not physically exist.

I assume it was introduced as a wrapper around smps7_reg
to provide a speaking signal name "vdds_1v8_main" as label.

This fixed-regulator without real function was not an issue
in driver code until

Commit 98e48cd9283d ("regulator: core: resolve supply for boot-on/always-on regulators")

introduced a new check for regulator initialization which
makes Palmas regulator registration fail:

[ 5.407712] ldo1: supplied by vsys_cobra
[ 5.412748] ldo2: supplied by vsys_cobra
[ 5.417603] palmas-pmic 48070000.i2c:palmas@48:palmas_pmic: failed to register 48070000.i2c:palmas@48:palmas_pmic regulator

The reason is that the supply-chain of regulators is too
long and goes from ldo3 through the virtual vdds_1v8_main
regulator and then back to smps7. This adds a cross-dependency
of probing Palmas regulators and the fixed-regulator which
leads to probe deferral by the new check and is no longer
resolved.

Since we do not control what device tree files including this
one reference (either &vdds_1v8_main or &smps7_reg or both)
we keep both labels for smps7 for compatibility.

Fixes: 98e48cd9283d ("regulator: core: resolve supply for boot-on/always-on regulators")
Signed-off-by: H. Nikolaus Schaller <[email protected]>
---
arch/arm/boot/dts/omap5-board-common.dtsi | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/arch/arm/boot/dts/omap5-board-common.dtsi b/arch/arm/boot/dts/omap5-board-common.dtsi
index d8f13626cfd1..3a8f10231475 100644
--- a/arch/arm/boot/dts/omap5-board-common.dtsi
+++ b/arch/arm/boot/dts/omap5-board-common.dtsi
@@ -30,14 +30,6 @@ vsys_cobra: fixedregulator-vsys_cobra {
regulator-max-microvolt = <5000000>;
};

- vdds_1v8_main: fixedregulator-vdds_1v8_main {
- compatible = "regulator-fixed";
- regulator-name = "vdds_1v8_main";
- vin-supply = <&smps7_reg>;
- regulator-min-microvolt = <1800000>;
- regulator-max-microvolt = <1800000>;
- };
-
vmmcsd_fixed: fixedregulator-mmcsd {
compatible = "regulator-fixed";
regulator-name = "vmmcsd_fixed";
@@ -487,6 +479,7 @@ smps6_reg: smps6 {
regulator-boot-on;
};

+ vdds_1v8_main:
smps7_reg: smps7 {
/* VDDS_1v8_OMAP over VDDS_1v8_MAIN */
regulator-name = "smps7";
--
2.31.1


2021-07-14 07:34:46

by H. Nikolaus Schaller

[permalink] [raw]
Subject: Re: [PATCH v2] omap5-board-common: remove not physically existing vdds_1v8_main fixed-regulator

Any comments?

> Am 01.07.2021 um 16:00 schrieb H. Nikolaus Schaller <[email protected]>:
>
> This device tree include file describes a fixed-regulator
> connecting smps7_reg output (1.8V) to some 1.8V rail and
> consumers (vdds_1v8_main).
>
> This regulator does not physically exist.
>
> I assume it was introduced as a wrapper around smps7_reg
> to provide a speaking signal name "vdds_1v8_main" as label.
>
> This fixed-regulator without real function was not an issue
> in driver code until
>
> Commit 98e48cd9283d ("regulator: core: resolve supply for boot-on/always-on regulators")
>
> introduced a new check for regulator initialization which
> makes Palmas regulator registration fail:
>
> [ 5.407712] ldo1: supplied by vsys_cobra
> [ 5.412748] ldo2: supplied by vsys_cobra
> [ 5.417603] palmas-pmic 48070000.i2c:palmas@48:palmas_pmic: failed to register 48070000.i2c:palmas@48:palmas_pmic regulator
>
> The reason is that the supply-chain of regulators is too
> long and goes from ldo3 through the virtual vdds_1v8_main
> regulator and then back to smps7. This adds a cross-dependency
> of probing Palmas regulators and the fixed-regulator which
> leads to probe deferral by the new check and is no longer
> resolved.
>
> Since we do not control what device tree files including this
> one reference (either &vdds_1v8_main or &smps7_reg or both)
> we keep both labels for smps7 for compatibility.
>
> Fixes: 98e48cd9283d ("regulator: core: resolve supply for boot-on/always-on regulators")
> Signed-off-by: H. Nikolaus Schaller <[email protected]>
> ---
> arch/arm/boot/dts/omap5-board-common.dtsi | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/arch/arm/boot/dts/omap5-board-common.dtsi b/arch/arm/boot/dts/omap5-board-common.dtsi
> index d8f13626cfd1..3a8f10231475 100644
> --- a/arch/arm/boot/dts/omap5-board-common.dtsi
> +++ b/arch/arm/boot/dts/omap5-board-common.dtsi
> @@ -30,14 +30,6 @@ vsys_cobra: fixedregulator-vsys_cobra {
> regulator-max-microvolt = <5000000>;
> };
>
> - vdds_1v8_main: fixedregulator-vdds_1v8_main {
> - compatible = "regulator-fixed";
> - regulator-name = "vdds_1v8_main";
> - vin-supply = <&smps7_reg>;
> - regulator-min-microvolt = <1800000>;
> - regulator-max-microvolt = <1800000>;
> - };
> -
> vmmcsd_fixed: fixedregulator-mmcsd {
> compatible = "regulator-fixed";
> regulator-name = "vmmcsd_fixed";
> @@ -487,6 +479,7 @@ smps6_reg: smps6 {
> regulator-boot-on;
> };
>
> + vdds_1v8_main:
> smps7_reg: smps7 {
> /* VDDS_1v8_OMAP over VDDS_1v8_MAIN */
> regulator-name = "smps7";
> --
> 2.31.1
>

2021-07-27 08:16:34

by Tony Lindgren

[permalink] [raw]
Subject: Re: [PATCH v2] omap5-board-common: remove not physically existing vdds_1v8_main fixed-regulator

* H. Nikolaus Schaller <[email protected]> [210714 07:33]:
> Any comments?

Seems like the way to go, applying into fixes.

Thanks,

Tony