Unverified Commit 4f3323b7 authored by André Draszik's avatar André Draszik Committed by Mark Brown
Browse files

regulator: core: streamline supply resolution for always-on/boot-on regulators 



For always-on and boot-on regulators, regulator_register() is currently
trying to anticipate the requirement to resolve a supply early.

Unfortunately, this code executes too early, before we have potentially
updated the regulator's always_on constraint as part of
set_machine_constraints(), causing it to miss cases.

Rather than trying to hack it more, just defer to the outcome of
set_machine_constraints(). The latter returns early (without doing any
regulator initialisation) with -EPROBE_DEFER as of commit 'regulator:
core: move supply check earlier in set_machine_constraints()' and is
therefore safe to call multiple times to determine if supplies need to
be resolved early.

Commit 8a866d52 ("regulator: core: Resolve supply name earlier to
prevent double-init") (later updated by
commit 520fb178 ("regulator: core: Fix regulator supply
registration with sysfs")) added these tests originally to avoid
calling set_machine_constraints() multiple times to try to avoid
voltage glitches due to all the regulator initialisation happening each
time. This isn't an issue anymore as per above.

Signed-off-by: default avatarAndré Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260109-regulators-defer-v2-4-1a25dc968e60@linaro.org


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 86a8eeb0

drivers/regulator/core.c

+4 −15
Original line number Diff line number Diff line
@@ -5937,7 +5937,6 @@ regulator_register(struct device *dev, 
	bool dangling_cfg_gpiod = false;

	bool dangling_of_gpiod = false;

	int ret, i;

	bool resolved_early = false;



	if (cfg == NULL)

		return ERR_PTR(-EINVAL);
@@ -6075,17 +6074,6 @@ regulator_register(struct device *dev, 
			goto wash;

	}



	if ((rdev->supply_name && !rdev->supply) &&

		(rdev->constraints->always_on ||

		 rdev->constraints->boot_on)) {

		ret = regulator_resolve_supply(rdev);

		if (ret)

			rdev_dbg(rdev, "unable to resolve supply early: %pe\n",

					 ERR_PTR(ret));



		resolved_early = true;

	}



	if (config->ena_gpiod) {

		ret = regulator_ena_gpio_request(rdev, config);

		if (ret != 0) {
@@ -6099,9 +6087,10 @@ regulator_register(struct device *dev, 
	}



	ret = set_machine_constraints(rdev);

	if (ret == -EPROBE_DEFER && !resolved_early) {

		/* Regulator might be in bypass mode and so needs its supply

		 * to set the constraints

	if (ret == -EPROBE_DEFER) {

		/* Regulator might be in bypass mode or an always-on or boot-on

		 * regulator and so needs its supply to set the constraints or

		 * for enable.

		 */

		/* FIXME: this currently triggers a chicken-and-egg problem

		 * when creating -SUPPLY symlink in sysfs to a regulator