linux.git/drivers/cpufreq/intel_pstate.c, branch v3.12 Linux kernel source tree intel_pstate: Correct calculation of min pstate value 2013-10-21T23:16:39+00:00 Dirk Brandewie dirk.j.brandewie@intel.com 2013-10-21T16:20:33+00:00 7244cb62d96e735847dc9d08f870550df896898c The minimum pstate is supposed to be a percentage of the maximum P state available. Calculate min using max pstate and not the current max which may have been limited by the user Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
The minimum pstate is supposed to be a percentage of the maximum P
state available.  Calculate min using max pstate and not the
current max which may have been limited by the user

Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_pstate: Improve accuracy by not truncating until final result 2013-10-21T23:15:38+00:00 Brennan Shacklett brennan@genyes.org 2013-10-21T16:20:32+00:00 d253d2a52676cfa3d89b8f0737a08ce7db665207 This patch addresses Bug 60727 (https://bugzilla.kernel.org/show_bug.cgi?id=60727) which was due to the truncation of intermediate values in the calculations, which causes the code to consistently underestimate the current cpu frequency, specifically 100% cpu utilization was truncated down to the setpoint of 97%. This patch fixes the problem by keeping the results of all intermediate calculations as fixed point numbers rather scaling them back and forth between integers and fixed point. References: https://bugzilla.kernel.org/show_bug.cgi?id=60727 Signed-off-by: Brennan Shacklett <bpshacklett@gmail.com> Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
This patch addresses Bug 60727
(https://bugzilla.kernel.org/show_bug.cgi?id=60727)
which was due to the truncation of intermediate values in the
calculations, which causes the code to consistently underestimate the
current cpu frequency, specifically 100% cpu utilization was truncated
down to the setpoint of 97%. This patch fixes the problem by keeping
the results of all intermediate calculations as fixed point numbers
rather scaling them back and forth between integers and fixed point.

References: https://bugzilla.kernel.org/show_bug.cgi?id=60727
Signed-off-by: Brennan Shacklett <bpshacklett@gmail.com>
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_pstate: Fix type mismatch warning 2013-10-16T20:59:33+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2013-10-16T20:59:33+00:00 09c87e2f79eb336bd313090be8113ae29345b8f5 The expression in line 398 of intel_pstate.c causes the following warning to be emitted: drivers/cpufreq/intel_pstate.c:398:3: warning: left shift count >= width of type which happens because unsigned long is 32-bit on some architectures. Fix that by using a helper u64 variable and simplify the code slightly. Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
The expression in line 398 of intel_pstate.c causes the following
warning to be emitted:

drivers/cpufreq/intel_pstate.c:398:3: warning: left shift count >= width of type

which happens because unsigned long is 32-bit on some architectures.

Fix that by using a helper u64 variable and simplify the code
slightly.

Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq / intel_pstate: Fix max_perf_pct on resume 2013-10-15T23:41:46+00:00 Dirk Brandewie dirk.j.brandewie@intel.com 2013-10-15T18:06:14+00:00 52e0a509e5d6f902ec26bc2a8bb02b137dc453be If the system is suspended while max_perf_pct is less than 100 percent or no_turbo set policy->{min,max} will be set incorrectly with scaled values which turn the scaled values into hard limits. References: https://bugzilla.kernel.org/show_bug.cgi?id=61241 Reported-by: Patrick Bartels <petzicus@googlemail.com> Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Cc: 3.9+ <stable@vger.kernel.org> # 3.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
If the system is suspended while max_perf_pct is less than 100 percent
or no_turbo set policy->{min,max} will be set incorrectly with scaled
values which turn the scaled values into hard limits.

References: https://bugzilla.kernel.org/show_bug.cgi?id=61241
Reported-by: Patrick Bartels <petzicus@googlemail.com>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Cc: 3.9+ <stable@vger.kernel.org> # 3.9+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_pstate: fix no_turbo 2013-10-01T20:51:11+00:00 Srinivas Pandruvada srinivas.pandruvada@linux.intel.com 2013-10-01T17:28:41+00:00 1ccf7a1cdafadd02e33e8f3d74370685a0600ec6 When sysfs for no_turbo is set, then also some p states in turbo regions are observed. This patch will set IDA Engage bit when no_turbo is set to explicitly disengage turbo. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
When sysfs for no_turbo is set, then also some p states in turbo regions
are observed. This patch will set IDA Engage bit when no_turbo is set to
explicitly disengage turbo.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_pstate: Add Haswell CPU models 2013-09-10T21:10:39+00:00 Nell Hardcastle nell@spicious.com 2013-06-30T22:58:57+00:00 6cdcdb793791f776ea9408581b1242b636d43b37 Enable the intel_pstate driver for Haswell CPUs. One missing Ivy Bridge model (0x3E) is also included. Models referenced from tools/power/x86/turbostat/turbostat.c:has_nehalem_turbo_ratio_limit Signed-off-by: Nell Hardcastle <nell@spicious.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Enable the intel_pstate driver for Haswell CPUs. One missing Ivy Bridge
model (0x3E) is also included. Models referenced from
tools/power/x86/turbostat/turbostat.c:has_nehalem_turbo_ratio_limit

Signed-off-by: Nell Hardcastle <nell@spicious.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Drop the owner field from struct cpufreq_driver 2013-08-10T01:24:47+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-08-06T17:23:12+00:00 adc97d6a735dbb1e94cb4f1bf0b55f258b349941 We don't need to set .owner = THIS_MODULE any more in cpufreq drivers as this field isn't used any more by the cpufreq core. This patch removes it and updates all dependent drivers accordingly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
We don't need to set .owner = THIS_MODULE any more in cpufreq drivers
as this field isn't used any more by the cpufreq core.

This patch removes it and updates all dependent drivers accordingly.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq / intel_pstate: Change to scale off of max P-state 2013-07-23T02:18:28+00:00 Dirk Brandewie dirk.j.brandewie@intel.com 2013-07-18T15:48:42+00:00 2134ed4d614349b2b4e8d7bb593baa9179b8dd1e Change to using max P-state instead of max turbo P-state. This change resolves two issues. On a quiet system intel_pstate can fail to respond to a load change. On CPU SKUs that have a limited number of P-states and no turbo range intel_pstate fails to select the highest available P-state. This change is suitable for stable v3.9+ References: https://bugzilla.kernel.org/show_bug.cgi?id=59481 Reported-and-tested-by: Arjan van de Ven <arjan@linux.intel.com> Reported-and-tested-by: dsmythies@telus.net Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 3.9+ <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Change to using max P-state instead of max turbo P-state.  This
change resolves two issues.

On a quiet system intel_pstate can fail to respond to a load change.

On CPU SKUs that have a limited number of P-states and no turbo range
intel_pstate fails to select the highest available P-state.

This change is suitable for stable v3.9+

References: https://bugzilla.kernel.org/show_bug.cgi?id=59481
Reported-and-tested-by: Arjan van de Ven <arjan@linux.intel.com>
Reported-and-tested-by: dsmythies@telus.net
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: delete __cpuinit usage from all cpufreq files 2013-07-14T23:36:57+00:00 Paul Gortmaker paul.gortmaker@windriver.com 2013-06-19T17:54:04+00:00 2760984f6578d5a462155bb4727766d0c8b68387 The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the drivers/cpufreq uses of the __cpuinit macros from all C files. [1] https://lkml.org/lkml/2013/5/20/589 [v2: leave 2nd lines of args misaligned as requested by Viresh] Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: cpufreq@vger.kernel.org Cc: linux-pm@vger.kernel.org Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> 
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the drivers/cpufreq uses of the __cpuinit macros
from all C files.

[1] https://lkml.org/lkml/2013/5/20/589

[v2: leave 2nd lines of args misaligned as requested by Viresh]
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: cpufreq@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
cpufreq / intel_pstate: Add additional supported CPU ID 2013-05-21T22:28:44+00:00 Dirk Brandewie dirk.j.brandewie@intel.com 2013-05-17T16:10:24+00:00 c96d53d600643ee0adfd1cb90814bd9510e62b71 Add CPU ID for Ivybrigde processor. Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Add CPU ID for Ivybrigde processor.

Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>