• Thomas Renninger's avatar
    PM QoS: Make pm_qos settings readable · f9b9e806
    Thomas Renninger authored
    I have a machine where entering deep C-states broke.
    pm_qos was a hot candidate, but I couldn't find any way to double
    check without the need of recompiling.
    
    While in this case it was a driver bug (ath9k):
    https://bugzilla.kernel.org/show_bug.cgi?id=27532
    
    powertop or others may want to read out cpu_dma_latency
    restrictions which could be the cause of preventing a machine
    entering deeper C-states.
    
    Output with this patch:
    
    # default value of 2000 * USEC_PER_SEC (0x77359400)
    cat /dev/network_latency |hexdump
    0000000 9400 7735
    0000004
    
    # value of 55 us which is the reason for not entering C2
    cat /dev/cpu_dma_latency |hexdump
    0000000 0037 0000
    0000004
    
    There is no reason to hide this info -> make pm_qos files readable.
    Signed-off-by: default avatarThomas Renninger <trenn@suse.de>
    Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
    f9b9e806
pm_qos_params.c 12.4 KB