]> www.infradead.org Git - users/jedix/linux-maple.git/commit
cpufreq: intel_pstate: Fix divide by zero on Knights Landing (KNL)
authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Thu, 15 Oct 2015 19:34:21 +0000 (12:34 -0700)
committerChuck Anderson <chuck.anderson@oracle.com>
Fri, 5 Feb 2016 03:28:29 +0000 (19:28 -0800)
commit0bba0b7bd50d0e1d46c5eec25ace72711df4dc01
tree0bca3966a3292dcd5ed7d6451be3dcd95f33df8b
parentcd56fa85ee10031d8fa7fb3305df067062a5dc0e
cpufreq: intel_pstate: Fix divide by zero on Knights Landing (KNL)

Orabug: 22623827

commit 8e601a9f97a00bab031980de34f9a81891c1f82f upstream.

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 <srinivas.pandruvada@linux.intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 82696471b9c72e4b996e009bb6b4ee432c175582)
Signed-off-by: Dan Duval <dan.duval@oracle.com>
drivers/cpufreq/intel_pstate.c