From: Javier Martinez Canillas Date: Tue, 7 Nov 2023 19:09:18 +0000 (+0100) Subject: regulator: core: Add option to prevent disabling unused regulators X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c986968fe92f20f2db26fa6bce27795b2e9ebe22;p=linux.git regulator: core: Add option to prevent disabling unused regulators This may be useful for debugging and develompent purposes, when there are drivers that depend on regulators to be enabled but do not request them. It is inspired from the clk_ignore_unused and pd_ignore_unused parameters, that are used to keep firmware-enabled clocks and power domains on even if these are not used by drivers. The parameter is not expected to be used in normal cases and should not be needed on a platform with proper driver support. Signed-off-by: Javier Martinez Canillas Reviewed-by: Brian Masney Acked-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20231107190926.1185326-1-javierm@redhat.com Signed-off-by: Mark Brown --- diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 65731b060e3fe..825159394da2a 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5544,6 +5544,13 @@ print every Nth verbose statement, where N is the value specified. + regulator_ignore_unused + [REGULATOR] + Prevents regulator framework from disabling regulators + that are unused, due no driver claiming them. This may + be useful for debug and development, but should not be + needed on a platform with proper driver support. + relax_domain_level= [KNL, SMP] Set scheduler's default relax_domain_level. See Documentation/admin-guide/cgroup-v1/cpusets.rst. diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 3137e40fcd3e0..79777495cc3a0 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -6234,6 +6234,14 @@ unlock: return 0; } +static bool regulator_ignore_unused; +static int __init regulator_ignore_unused_setup(char *__unused) +{ + regulator_ignore_unused = true; + return 1; +} +__setup("regulator_ignore_unused", regulator_ignore_unused_setup); + static void regulator_init_complete_work_function(struct work_struct *work) { /* @@ -6246,6 +6254,15 @@ static void regulator_init_complete_work_function(struct work_struct *work) class_for_each_device(®ulator_class, NULL, NULL, regulator_register_resolve_supply); + /* + * For debugging purposes, it may be useful to prevent unused + * regulators from being disabled. + */ + if (regulator_ignore_unused) { + pr_warn("regulator: Not disabling unused regulators\n"); + return; + } + /* If we have a full configuration then disable any regulators * we have permission to change the status for and which are * not in use or always_on. This is effectively the default