From: Lukasz Luba lukasz.luba@arm.com
[ Upstream commit fb9d62b27ab1e07d625591549c314b7d406d21df ]
The debugfs directory '/sys/kernel/debug/energy_model' is needed before the Energy Model registration can happen. With the recent change in debugfs subsystem it's not allowed to create this directory at early stage (core_initcall). Thus creating this directory would fail.
Postpone the creation of the EM debug dir to later stage: fs_initcall.
It should be safe since all clients: CPUFreq drivers, Devfreq drivers will be initialized in later stages.
The custom debug log below prints the time of creation the EM debug dir at fs_initcall and successful registration of EMs at later stages.
[ 1.505717] energy_model: creating rootdir [ 3.698307] cpu cpu0: EM: created perf domain [ 3.709022] cpu cpu1: EM: created perf domain
Fixes: 56348560d495 ("debugfs: do not attempt to create a new file before the filesystem is initalized") Reported-by: Ionela Voinescu ionela.voinescu@arm.com Signed-off-by: Lukasz Luba lukasz.luba@arm.com Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/power/energy_model.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 1358fa4abfa8..0f4530b3a8cd 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -98,7 +98,7 @@ static int __init em_debug_init(void)
return 0; } -core_initcall(em_debug_init); +fs_initcall(em_debug_init); #else /* CONFIG_DEBUG_FS */ static void em_debug_create_pd(struct device *dev) {} static void em_debug_remove_pd(struct device *dev) {}