linux-kernel - [PATCH 1/2] regulator: core: resolve supply for boot-on/always-on regulators

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Date:   Thu, 20 May 2021 01:12:23 +0300
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>
Cc:     Michał Mirosław <mirq-linux@...e.qmqm.pl>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] regulator: core: resolve supply for boot-on/always-on regulators

For the boot-on/always-on regulators the set_machine_constrainst() is
called before resolving rdev->supply. Thus the code would try to enable
rdev before enabling supplying regulator. Enforce resolving supply
regulator before enabling rdev.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
---
 drivers/regulator/core.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index f192bf19492e..e20e77e4c159 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1425,6 +1425,12 @@ static int set_machine_constraints(struct regulator_dev *rdev)
 	 * and we have control then make sure it is enabled.
 	 */
 	if (rdev->constraints->always_on || rdev->constraints->boot_on) {
+		/* If we want to enable this regulator, make sure that we know
+		 * the supplying regulator.
+		 */
+		if (rdev->supply_name && !rdev->supply)
+			return -EPROBE_DEFER;
+
 		if (rdev->supply) {
 			ret = regulator_enable(rdev->supply);
 			if (ret < 0) {
-- 
2.30.2