From: Romain Gantois Date: Tue, 29 Jul 2025 09:50:57 +0000 (+0200) Subject: regulator: core: correct convergence check in regulator_set_voltage() X-Git-Tag: v6.17-rc1~12^2 X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=10dfd36f078423c51602a9a21ed85e8e6c947a00;p=thirdparty%2Flinux.git regulator: core: correct convergence check in regulator_set_voltage() The logic in regulator_set_voltage() which checks for a non-convergence condition on a stepped regulator is flawed. regulator_set_voltage() checks if the error in target voltage has increased or decreased, and returns -EWOULDBLOCK if the error has not decreased enough. The correct non-convergence condition is: new_delta - delta > -rdev->constraints->max_uV_step or equivalently: delta - new_delta < rdev->constraints->max_uV_step But the currently used condition is: new_delta - delta > rdev->constraints->max_uV_step Which may cause an infinite loop if the voltage error doesn't converge. Fix this by correcting the convergence condition. Suggested-by: Jon Hunter Fixes: d511206dc7443 ("regulator: core: repeat voltage setting request for stepped regulators") Signed-off-by: Romain Gantois Link: https://patch.msgid.link/20250729-b4-regulator-stepping-fix-v1-1-3f7b8c55d7d7@bootlin.com Tested-by: Jon Hunter Reviewed-by: Jon Hunter Signed-off-by: Mark Brown --- diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 8ed9b96518cf5..554d83c4af0c1 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -3884,7 +3884,7 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, new_delta = ret; /* check that voltage is converging quickly enough */ - if (new_delta - delta > rdev->constraints->max_uV_step) { + if (delta - new_delta < rdev->constraints->max_uV_step) { ret = -EWOULDBLOCK; goto out; }