Revert part of commit 75c0758137c7a
("acpi-cpufreq: Fail initialization if driver cannot be registered").
acpi-cpufreq is mutually exclusive with intel_pstate, however,
acpi-cpufreq is loaded multiple times during startup while intel_pstate is
enabled. On systems using systemd the kernel triggers one uevent for each
device as a result of systemd-udev-trigger.service. The service exists to
retrigger all devices as uevents sent by the kernel before systemd-udevd
is running are missed. The delay caused by systemd-udevd repeatedly loading
the driver, getting a fail return, and unloading the driver twice per
logical CPU has a significant impact on the startup time, and can cause
some devices to be unavailable after reaching the root login prompt.
Load the driver once but skip initialization if a cpufreq driver exists by
changing the return value of cpufreq_get_current_driver() from -EEXIST to
0.
Signed-off-by: Kyle Meyer <kyle.meyer@xxxxxxx>
---
drivers/cpufreq/acpi-cpufreq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 7e7450453714..e79a945369d1 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -1003,7 +1003,7 @@ static int __init acpi_cpufreq_init(void)
/* don't keep reloading if cpufreq_driver exists */
if (cpufreq_get_current_driver())
- return -EEXIST;
+ return 0;
pr_debug("%s\n", __func__);
--
2.26.2
