5.4-stable review patch. If anyone has any objections, please let me know.
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From: Len Brown len.brown@intel.com
[ Upstream commit c97c057d357c4b39b153e9e430bbf8976e05bd4e ]
On enabling HWP, preserve the reserved bits in MSR_PM_ENABLE.
Also, skip writing the MSR_PM_ENABLE if HWP is already enabled.
Signed-off-by: Len Brown len.brown@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- .../x86_energy_perf_policy/x86_energy_perf_policy.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c index 165eb4da8a644..0cb17e13c002b 100644 --- a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c +++ b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c @@ -1024,13 +1024,18 @@ int update_hwp_request_pkg(int pkg)
int enable_hwp_on_cpu(int cpu) { - unsigned long long msr; + unsigned long long old_msr, new_msr; + + get_msr(cpu, MSR_PM_ENABLE, &old_msr); + + if (old_msr & 1) + return 0; /* already enabled */
- get_msr(cpu, MSR_PM_ENABLE, &msr); - put_msr(cpu, MSR_PM_ENABLE, 1); + new_msr = old_msr | 1; + put_msr(cpu, MSR_PM_ENABLE, new_msr);
if (verbose) - printf("cpu%d: MSR_PM_ENABLE old: %d new: %d\n", cpu, (unsigned int) msr, 1); + printf("cpu%d: MSR_PM_ENABLE old: %llX new: %llX\n", cpu, old_msr, new_msr);
return 0; }