6.6-stable review patch. If anyone has any objections, please let me know.
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From: Gabor Juhos j4g8y7@gmail.com
[ Upstream commit fb1ebb10468da414d57153ddebaab29c38ef1a78 ]
For 'always-on' and 'boot-on' regulators, the set_machine_constraints() may enable supply before enabling the main regulator, however if the latter fails, the function returns with an error but the supply remains enabled.
When this happens, the regulator_register() function continues on the error path where it puts the supply regulator. Since enabling the supply is not balanced with a disable call, a warning similar to the following gets issued from _regulator_put():
[ 1.603889] WARNING: CPU: 2 PID: 44 at _regulator_put+0x8c/0xa0 [ 1.603908] Modules linked in: [ 1.603926] CPU: 2 UID: 0 PID: 44 Comm: kworker/u16:3 Not tainted 6.18.0-rc4 #0 NONE [ 1.603938] Hardware name: Qualcomm Technologies, Inc. IPQ9574/AP-AL02-C7 (DT) [ 1.603945] Workqueue: async async_run_entry_fn [ 1.603958] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 1.603967] pc : _regulator_put+0x8c/0xa0 [ 1.603976] lr : _regulator_put+0x7c/0xa0 ... [ 1.604140] Call trace: [ 1.604145] _regulator_put+0x8c/0xa0 (P) [ 1.604156] regulator_register+0x2ec/0xbf0 [ 1.604166] devm_regulator_register+0x60/0xb0 [ 1.604178] rpm_reg_probe+0x120/0x208 [ 1.604187] platform_probe+0x64/0xa8 ...
In order to avoid this, change the set_machine_constraints() function to disable the supply if enabling the main regulator fails.
Fixes: 05f224ca6693 ("regulator: core: Clean enabling always-on regulators + their supplies") Signed-off-by: Gabor Juhos j4g8y7@gmail.com Link: https://patch.msgid.link/20251107-regulator-disable-supply-v1-1-c95f0536f1b5... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/regulator/core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 1d49612eeb7e5..465f4f870162f 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1653,6 +1653,8 @@ 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) { + bool supply_enabled = false; + /* If we want to enable this regulator, make sure that we know * the supplying regulator. */ @@ -1672,11 +1674,14 @@ static int set_machine_constraints(struct regulator_dev *rdev) rdev->supply = NULL; return ret; } + supply_enabled = true; }
ret = _regulator_do_enable(rdev); if (ret < 0 && ret != -EINVAL) { rdev_err(rdev, "failed to enable: %pe\n", ERR_PTR(ret)); + if (supply_enabled) + regulator_disable(rdev->supply); return ret; }