From 57919f4a2ea47f75ac6117f7d99831f7fbd89bc7 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Wed, 24 Aug 2022 14:22:57 -0700 Subject: [PATCH] regulator: core: Don't err if allow-set-load but no allowed-modes Apparently the device trees of some boards have the property "regulator-allow-set-load" for some of their regulators but then they don't specify anything for "regulator-allowed-modes". That's not really legit, but... ...before commit efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()") they used to get away with it, at least on boards using RPMH regulators. That's because when a regulator driver implements set_load() then the core doesn't look at "regulator-allowed-modes" when trying to automatically adjust things in response to the regulator's load. The core doesn't know what mode we'll end up in, so how could it validate it? Said another way: before commit efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()") some boards _were_ having the regulator mode adjusted despite listing no allowed modes. After commit efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()") these same boards were now getting an error returned when trying to use their regulators, since simply enabling a regulator tries to update its load and that was failing. We don't really want to go back to the behavior from before commit efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()"). Boards shouldn't have been changing modes if no allowed modes were listed. However, the behavior after commit efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()") isn't the best because now boards can't even turn their regulators on. Let's choose to detect this case and return "no error" from drms_uA_update(). The net-result will be _different_ behavior than we had before commit efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()"), but this new behavior seems more correct. If a board truly needed the mode switched then its device tree should be updated to list the allowed modes. Reported-by: Andrew Halaney Fixes: efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()") Signed-off-by: Douglas Anderson Tested-by: Andrew Halaney Link: https://lore.kernel.org/r/20220824142229.RFT.v2.2.I6f77860e5cd98bf5c67208fa9edda4a08847c304@changeid Signed-off-by: Mark Brown --- drivers/regulator/core.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index fd8582d7e2c0..c17d3418d7bf 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -977,6 +977,18 @@ static int drms_uA_update(struct regulator_dev *rdev) rdev_err(rdev, "failed to set load %d: %pe\n", current_uA, ERR_PTR(err)); } else { + /* + * Unfortunately in some cases the constraints->valid_ops has + * REGULATOR_CHANGE_DRMS but there are no valid modes listed. + * That's not really legit but we won't consider it a fatal + * error here. We'll treat it as if REGULATOR_CHANGE_DRMS + * wasn't set. + */ + if (!rdev->constraints->valid_modes_mask) { + rdev_dbg(rdev, "Can change modes; but no valid mode\n"); + return 0; + } + /* get output voltage */ output_uV = regulator_get_voltage_rdev(rdev);