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From:   "H. Nikolaus Schaller" <hns@goldelico.com>
To:     Tony Lindgren <tony@atomide.com>, gg@slimlogic.co.uk,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>, Nishanth Menon <nm@ti.com>,
        peter.ujfalusi@gmail.com,
        =?UTF-8?q?Beno=C3=AEt=20Cousson?= <bcousson@baylibre.com>,
        Rob Herring <robh+dt@kernel.org>
Cc:     linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org,
        letux-kernel@openphoenux.org, kernel@pyra-handheld.com,
        devicetree@vger.kernel.org,
        "H. Nikolaus Schaller" <hns@goldelico.com>
Subject: [PATCH v2] omap5-board-common: remove not physically existing vdds_1v8_main fixed-regulator
Date:   Thu,  1 Jul 2021 16:00:22 +0200
Message-Id: <e836d5d98b028bdbb8805bcf79489e0df28add6c.1625148021.git.hns@goldelico.com>
MIME-Version: 1.0
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Precedence: bulk

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 <hns@goldelico.com>
---
 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