cpufreq: intel_pstate: Fix divide by zero on Knights Landing (KNL)
cpufreq: intel_pstate: Fix divide by zero on Knights Landing (KNL)

This is a workaround for KNL platform, where in some cases MPERF counter
will not have updated value before next read of MSR_IA32_MPERF. In this
case divide by zero will occur. This change ignores current sample for
busy calculation in this case.

Fixes: b34ef932d79a (intel_pstate: Knights Landing support)
Signed-off-by: Srinivas Pandruvada <910e550f1c830a1d246b6c3ed4d6ca559ba95c19@linux.intel.com>
Acked-by: Kristen Carlson Accardi <047ff8258f0113ece56e5e2fe9e0d987b14c4333@linux.intel.com>
Cc: 4.1+ <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org> # 4.1+
Signed-off-by: Rafael J. Wysocki <27ffc44a8ec6a212fba98cfc3246c6ce8ab131e0@intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs