From 86a8eeb0e913f4b6a55dabba5122098d4e805e55 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Andr=C3=A9=20Draszik?= Date: Fri, 9 Jan 2026 08:38:39 +0000 Subject: [PATCH] regulator: core: move supply check earlier in set_machine_constraints() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Since commit 98e48cd9283d ("regulator: core: resolve supply for boot-on/always-on regulators"), set_machine_constraints() can return -EPROBE_DEFER very late, after it has done a lot of work and configuration of the regulator. This means that configuration will happen multiple times for no benefit in that case. Furthermore, this can lead to timing-dependent voltage glitches as mentioned e.g. in commit 8a866d527ac0 ("regulator: core: Resolve supply name earlier to prevent double-init"). We can know that it's going to fail very early, in particular before going through the complete regulator configuration by moving some code around a little. Do so to avoid re-configuring the regulator multiple times, also avoiding the voltage glitches if we can. Fixes: 98e48cd9283d ("regulator: core: resolve supply for boot-on/always-on regulators") Signed-off-by: André Draszik Link: https://patch.msgid.link/20260109-regulators-defer-v2-3-1a25dc968e60@linaro.org Signed-off-by: Mark Brown --- drivers/regulator/core.c | 55 ++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 25 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 48c091de68d81..9ce0eef1dcfcb 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1444,6 +1444,33 @@ static int set_machine_constraints(struct regulator_dev *rdev) int ret = 0; const struct regulator_ops *ops = rdev->desc->ops; + /* + * If there is no mechanism for controlling the regulator then + * flag it as always_on so we don't end up duplicating checks + * for this so much. Note that we could control the state of + * a supply to control the output on a regulator that has no + * direct control. + */ + if (!rdev->ena_pin && !ops->enable) { + if (rdev->supply_name && !rdev->supply) + return -EPROBE_DEFER; + + if (rdev->supply) + rdev->constraints->always_on = + rdev->supply->rdev->constraints->always_on; + else + rdev->constraints->always_on = true; + } + + /* + * If we want to enable this regulator, make sure that we know the + * supplying regulator. + */ + if (rdev->constraints->always_on || rdev->constraints->boot_on) { + if (rdev->supply_name && !rdev->supply) + return -EPROBE_DEFER; + } + ret = machine_constraints_voltage(rdev, rdev->constraints); if (ret != 0) return ret; @@ -1609,37 +1636,15 @@ static int set_machine_constraints(struct regulator_dev *rdev) } } - /* - * If there is no mechanism for controlling the regulator then - * flag it as always_on so we don't end up duplicating checks - * for this so much. Note that we could control the state of - * a supply to control the output on a regulator that has no - * direct control. - */ - if (!rdev->ena_pin && !ops->enable) { - if (rdev->supply_name && !rdev->supply) - return -EPROBE_DEFER; - - if (rdev->supply) - rdev->constraints->always_on = - rdev->supply->rdev->constraints->always_on; - else - rdev->constraints->always_on = true; - } - /* If the constraints say the regulator should be on at this point * and we have control then make sure it is enabled. */ if (rdev->constraints->always_on || rdev->constraints->boot_on) { bool supply_enabled = false; - /* 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 supplying regulator has already been enabled, + /* We have ensured a potential supply has been resolved above. + * + * If supplying regulator has already been enabled, * it's not intended to have use_count increment * when rdev is only boot-on. */ -- 2.47.3