From d020283dc694c9ec31b410f522252f7a8397e67d Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Fri, 3 Feb 2012 22:22:25 +0100 Subject: [PATCH] PM / QoS: CPU C-state breakage with PM Qos change Looks like change "PM QoS: Move and rename the implementation files" merged during the 3.2 development cycle made PM QoS depend on CONFIG_PM which depends on (PM_SLEEP || PM_RUNTIME). That breaks CPU C-states with kernels not having these CONFIGs, causing CPUs to spend time in Polling loop idle instead of going into deep C-states, consuming way way more power. This is with either acpi idle or intel idle enabled. Either CONFIG_PM should be enabled with any pm_qos users or the !CONFIG_PM pm_qos_request() should return sane defaults not to break the existing users. Here's is the patch for the latter option. [rjw: Modified the changelog slightly.] Signed-off-by: Venkatesh Pallipadi Signed-off-by: Rafael J. Wysocki Cc: stable@vger.kernel.org --- include/linux/pm_qos.h | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index e5bbcbaa6f57..4d99e4e6ef83 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -110,7 +110,19 @@ static inline void pm_qos_remove_request(struct pm_qos_request *req) { return; } static inline int pm_qos_request(int pm_qos_class) - { return 0; } +{ + switch (pm_qos_class) { + case PM_QOS_CPU_DMA_LATENCY: + return PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; + case PM_QOS_NETWORK_LATENCY: + return PM_QOS_NETWORK_LAT_DEFAULT_VALUE; + case PM_QOS_NETWORK_THROUGHPUT: + return PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE; + default: + return PM_QOS_DEFAULT_VALUE; + } +} + static inline int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) { return 0; } -- 2.30.2