Public bug reported:

[ Impact ]

This patch series is part of the effort to enable Zen 6 client platform
support on Ubuntu Stonking kernel.

EPP works differently in Zen6 client than in previous programs.  We now
need some tuning data on a per core basis in amd-pstate to make sure
that it behaves effectively.

[ Fix ]

Pick up the following patch:

1. [PATCH v3 0/3] Add support for Zen 6 client EPP tunings

Which has been included in linux-next

[ Test plan ]

This can be tested by hooking into event "amd_cpu:amd_pstate_epp_perf"
with ftrace:

$ trace-cmd stream -e amd_cpu:amd_pstate_epp_perf

When toggling
/sys/device/system/cpu/cpufreq/policyX/energy_performance_preference,
the tracepoint ouput shows the EPP values changed to the values
accordingly (performance, balance_performance, balance_power, power
respectively):

1. performance core: 25, 51, 64, 64
2. low_power core: 25, 51, 64, 115
3. efficiency core: 25, 51, 64, 115

[ Where problems could occur ]

This may include refactor of EPP lookup logic in amd-pmc driver. Errors
in those refactors may lead to wrongly calculated EPP on older
platforms.

[ Additional information ]

[1] https://lore.kernel.org/linux-
pm/[email protected]/

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

** Description changed:

  [ Impact ]
+ 
+ This patch series is part of the effort to enable Zen 6 client platform
+ support on Ubuntu Stonking kernel.
  
  EPP works differently in Zen6 client than in previous programs.  We now
  need some tuning data on a per core basis in amd-pstate to make sure
  that it behaves effectively.
- 
  
  [ Fix ]
  
  Pick up the following patch:
  
  1. [PATCH v3 0/3] Add support for Zen 6 client EPP tunings
  
  Which has been included in linux-next
- 
  
  [ Test plan ]
  
  This can be tested by hooking into event "amd_cpu:amd_pstate_epp_perf"
  with ftrace:
  
  $ trace-cmd stream -e amd_cpu:amd_pstate_epp_perf
  
  When toggling
  /sys/device/system/cpu/cpufreq/policyX/energy_performance_preference,
  the tracepoint ouput shows the EPP values changed to the values
  accordingly (performance, balance_performance, balance_power, power
  respectively):
  
  1. performance core: 25, 51, 64, 64
  2. low_power core: 25, 51, 64, 115
  3. efficiency core: 25, 51, 64, 115
  
- 
  [ Where problems could occur ]
  
  This may include refactor of EPP lookup logic in amd-pmc driver. Errors
  in those refactors may lead to wrongly calculated EPP on older
  platforms.
  
- 
  [ Additional information ]
  
  [1] https://lore.kernel.org/linux-
  pm/[email protected]/

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https://bugs.launchpad.net/bugs/2167558

Title:
  Add support for Zen6 EPP tunings

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