ffa5096a7c
Add EPP driver support for AMD SoCs which support a dedicated MSR for CPPC. EPP is used by the DPM controller to configure the frequency that a core operates at during short periods of activity. The SoC EPP targets are configured on a scale from 0 to 255 where 0 represents maximum performance and 255 represents maximum efficiency. The amd-pstate driver exports profile string names to userspace that are tied to specific EPP values. The balance_performance string (0x80) provides the best balance for efficiency versus power on most systems, but users can choose other strings to meet their needs as well. $ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_available_preferences default performance balance_performance balance_power power $ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_preference balance_performance To enable the driver,it needs to add `amd_pstate=active` to kernel command line and kernel will load the active mode epp driver Acked-by: Huang Rui <ray.huang@amd.com> Reviewed-by: Mario Limonciello <Mario.Limonciello@amd.com> Reviewed-by: Wyes Karny <wyes.karny@amd.com> Tested-by: Wyes Karny <wyes.karny@amd.com> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
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| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||