• Srinivas Pandruvada's avatar
    cpufreq: intel_pstate: Fix cpuinfo_max_freq when MSR_TURBO_RATIO_LIMIT is 0 · 4daca379
    Srinivas Pandruvada authored
    The MSR_TURBO_RATIO_LIMIT can be 0. This is not an error. User can update
    this MSR via BIOS settings on some systems or can use msr tools to update.
    Also some systems boot with value = 0.
    
    This results in display of cpufreq/cpuinfo_max_freq wrong. This value
    will be equal to cpufreq/base_frequency, even though turbo is enabled.
    
    But platform will still function normally in HWP mode as we get max
    1-core frequency from the MSR_HWP_CAPABILITIES. This MSR is already used
    to calculate cpu->pstate.turbo_freq, which is used for to set
    policy->cpuinfo.max_freq. But some other places cpu->pstate.turbo_pstate
    is used. For example to set policy->max.
    
    To fix this, also update cpu->pstate.turbo_pstate when updating
    cpu->pstate.turbo_freq.
    Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    4daca379
intel_pstate.c 72.4 KB