• Viresh Kumar's avatar
    PM / OPP: Add 'UNKNOWN' status for shared_opp in struct opp_table · 79ee2e8f
    Viresh Kumar authored
    dev_pm_opp_get_sharing_cpus() returns 0 even in the case when the OPP
    core doesn't know whether or not the table is shared. It works on the
    majority of platforms, where the OPP table is never created before
    invoking the function and then -ENODEV is returned by it.
    
    But in the case of one platform (Jetson TK1) at least, the situation
    is a bit different. The OPP table has been created (somehow) before
    dev_pm_opp_get_sharing_cpus() is called and it returns 0. Its caller
    treats that as 'the CPUs don't share OPPs' and that leads to degraded
    performance.
    
    Fix this by converting 'shared_opp' in struct opp_table to an enum
    and making dev_pm_opp_get_sharing_cpus() return -EINVAL in case when
    the value of that field is "access unknown", so that the caller can
    handle it accordingly (cpufreq-dt considers that as 'all CPUs share
    the table', for example).
    
    Fixes: 6f707daa "PM / OPP: Add dev_pm_opp_get_sharing_cpus()"
    Reported-and-tested-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
    Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
    [ rjw : Subject & changelog ]
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    79ee2e8f
opp.h 7.42 KB