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[Leann Ogasawara <leann.ogasawara@xxxxxxxxxxxxx>]

** Changed in: linux (Ubuntu)
   Importance: Undecided => Medium

** Changed in: linux (Ubuntu)
       Status: New => Triaged

** Changed in: linux (Ubuntu)
     Assignee: Taco Screen team (taco-screen-team) => Canonical Kernel Team (canonical-kernel-team)

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https://bugs.launchpad.net/bugs/1480894

Title:
  Frequency in Psafe after an OCC reset cycle while using performance
  governor

Status in linux package in Ubuntu:
  Triaged

Bug description:
  == Comment: #0 - Shilpasri G. Bhat <shigbhat@xxxxxxxxxx> - 2015-05-08 14:27:37 ==
  ---Problem Description---
  Frequency is not restored on a reset-cycle of OCC which can lead to performance degradation when using performance-governor. When OCC is reset it forces the cpu to safe frequency, after OCC becomes active again the frequency is not restored to max frequency if the governor is performance-governor or  to the last requested frequency for other static governors.
   
  Contact Information = Shilpasri G Bhat / shilpa.bhat@xxxxxxxxxxxxxxxxxx 
   
  ---Steps to Reproduce---
  1) select performance governor
  2) OCC reset cycle

  Fix for this is posted to lkml:
  https://lkml.org/lkml/2015/5/4/136

  == Comment: #1 - Shilpasri G. Bhat <shigbhat@xxxxxxxxxx> - 2015-08-03 06:56:15 ==
  Fyi ... v4 of the patches which were posted at
  https://lkml.org/lkml/2015/7/13/375
  ("[PATCH v4 0/6] powernv: cpufreq: Report frequency throttle by OCC")
  with the following 6 patches:
  cpufreq: powernv: Handle throttling due to Pmax capping at chip level
  powerpc/powernv: Add definition of OPAL_MSG_OCC message type
  cpufreq: powernv: Register for OCC related opal_message notification
  cpufreq: powernv: Call throttle_check() on receiving OCC_THROTTLE
  cpufreq: powernv: Report Psafe only if PMSR.psafe_mode_active bit is set
  cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling
  .
  ... is now accepted upstream as follows:
  1) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=053819e0bf8407746cc5febf7a4947bee50377b4
  ("cpufreq: powernv: Handle throttling due to Pmax capping at chip level")
  .
  2) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=196ba2d514a13f6af1b3d78de71ce74ed2fc8bdc
  ("powerpc/powernv: Add definition of OPAL_MSG_OCC message type")
  .
  3) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=cb166fa937a2fbc14badcafca86202354c34a213
  ("cpufreq: powernv: Register for OCC related opal_message notification")
  .
  4) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=735366fc407755626058218fc8d0430735a669ac
  ("cpufreq: powernv: Call throttle_check() on receiving OCC_THROTTLE")
  .
  5) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=3dd3ebe5bb3837aeac28a23f8f22b97cb84abab6
  ("cpufreq: powernv: Report Psafe only if PMSR.psafe_mode_active bit is set")
  .
  6) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=227942809b52f23cda414858b635c0285f11de00
  ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")

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