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[Bug 1480894] [NEW] Frequency in Psafe after an OCC reset cycle while using performance governor

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From: Launchpad Bug Tracker <1480894@xxxxxxxxxxxxxxxxxx>
Date: Tue, 18 Aug 2015 20:36:32 -0000
Reply-to: Bug 1480894 <1480894@xxxxxxxxxxxxxxxxxx>
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== 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")

** Affects: linux (Ubuntu)
     Importance: Undecided
     Assignee: Taco Screen team (taco-screen-team)
         Status: New


** Tags: architecture-ppc64le bot-comment bugnameltc-124851 severity-medium targetmilestone-inin1504
-- 
Frequency in Psafe after an OCC reset cycle while using performance governor
https://bugs.launchpad.net/bugs/1480894
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