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* [PATCH -v2] cpufreq: skip loading acpi_cpufreq after intel_pstate
@ 2013-09-20 17:43 Yinghai Lu
  2013-09-20 19:51 ` Yinghai Lu
  2013-09-26  5:17 ` Yinghai Lu
  0 siblings, 2 replies; 5+ messages in thread
From: Yinghai Lu @ 2013-09-20 17:43 UTC (permalink / raw)
  To: Rafael J. Wysocki, Viresh Kumar
  Cc: cpufreq, linux-acpi, linux-pm, linux-kernel, Yinghai Lu

If the hw support intel_pstate and acpi_cpufreq, intel_pstate will
get loaded first.

acpi_cpufreq_init will call acpi_cpufreq_early_init()
and that will allocate perf data and init those perf data in ACPI core,
(that will cover all cpus). But later it will free them as
cpufreq_register_driver(acpi_cpufreq) will fail as init_pstate is
already registered

Use cpufreq_get_current_driver() to check if we can skip the
acpi_cpufreq loading.

-v2: update changelog and separate second part to another patch, according
     to Viresh.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 drivers/cpufreq/acpi-cpufreq.c |    4 ++++
 1 file changed, 4 insertions(+)

Index: linux-2.6/drivers/cpufreq/acpi-cpufreq.c
===================================================================
--- linux-2.6.orig/drivers/cpufreq/acpi-cpufreq.c
+++ linux-2.6/drivers/cpufreq/acpi-cpufreq.c
@@ -986,6 +986,10 @@ static int __init acpi_cpufreq_init(void
 {
 	int ret;
 
+	/* don't keep reloading if cpufreq_driver exists */
+	if (cpufreq_get_current_driver())
+		return 0;
+
 	if (acpi_disabled)
 		return 0;
 

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2013-09-26 15:41 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2013-09-20 17:43 [PATCH -v2] cpufreq: skip loading acpi_cpufreq after intel_pstate Yinghai Lu
2013-09-20 19:51 ` Yinghai Lu
2013-09-26  5:17 ` Yinghai Lu
2013-09-26  5:40   ` Viresh Kumar
2013-09-26 15:41     ` Yinghai Lu

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