From 6d30fc511bec82dd8801b9bb8718cbeea1366ad8 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Mon, 9 Dec 2019 12:52:39 +0000 Subject: regulator: core: avoid unneeded .list_voltage calls Inside machine_constraints_voltage() a loop is in charge of verifying that each of the defined voltages are within the configured constraints and that those constraints are in fact compatible with the available voltages' list. When the registered regulator happens to be defined with a wide range of possible voltages the above O(n) loop can be costly. Moreover since this behaviour is triggered during the registration process, it means also that it can be easily triggered at probe time, slowing down considerably some module loading. On the other side if such wide range of voltage values happens to be also continuous and without discontinuity of any kind, the above potentially cumbersome operation is also useless. For these reasons, avoid such .list_voltage poll loop when regulator is described as 'continuous_voltage_range' as is, indeed, similarly already done inside regulator_is_supported_voltage(). Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20191209125239.46054-1-cristian.marussi@arm.com Signed-off-by: Mark Brown --- drivers/regulator/core.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/regulator') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 2c3a03cfd381..2961ac08d1ae 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1198,6 +1198,10 @@ static int machine_constraints_voltage(struct regulator_dev *rdev, return -EINVAL; } + /* no need to loop voltages if range is continuous */ + if (rdev->desc->continuous_voltage_range) + return 0; + /* initial: [cmin..cmax] valid, [min_uV..max_uV] not */ for (i = 0; i < count; i++) { int value; -- cgit v1.2.3