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    PM / QoS: CPU C-state breakage with PM Qos change · d020283d
    Venkatesh Pallipadi 提交于
    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: NVenkatesh Pallipadi <venki@google.com>
    Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
    Cc: stable@vger.kernel.org
    d020283d
pm_qos.h 5.7 KB