This is a note to let you know that I've just added the patch titled
intel_pstate: Fix BYT frequency reporting
to the 3.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
intel_pstate-fix-byt-frequency-reporting.patch
and it can be found in the queue-3.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b27580b05e6f5253228debc60b8ff4a786ff573a Mon Sep 17 00:00:00 2001
From: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>
Date: Mon, 13 Oct 2014 08:37:43 -0700
Subject: intel_pstate: Fix BYT frequency reporting
From: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>
commit b27580b05e6f5253228debc60b8ff4a786ff573a upstream.
BYT has a different conversion from P state to frequency than the core
processors. This causes the min/max and current frequency to be
misreported on some BYT SKUs. Tested on BYT N2820, Ivybridge and
Haswell processors.
Link: https://bugzilla.yoctoproject.org/show_bug.cgi?id=6663
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 42 +++++++++++++++++++++++++++++++++++------
1 file changed, 36 insertions(+), 6 deletions(-)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -64,6 +64,7 @@ struct pstate_data {
int current_pstate;
int min_pstate;
int max_pstate;
+ int scaling;
int turbo_pstate;
};
@@ -113,6 +114,7 @@ struct pstate_funcs {
int (*get_max)(void);
int (*get_min)(void);
int (*get_turbo)(void);
+ int (*get_scaling)(void);
void (*set)(struct cpudata*, int pstate);
void (*get_vid)(struct cpudata *);
};
@@ -433,6 +435,22 @@ static void byt_set_pstate(struct cpudat
wrmsrl(MSR_IA32_PERF_CTL, val);
}
+#define BYT_BCLK_FREQS 5
+static int byt_freq_table[BYT_BCLK_FREQS] = { 833, 1000, 1333, 1167, 800};
+
+static int byt_get_scaling(void)
+{
+ u64 value;
+ int i;
+
+ rdmsrl(MSR_FSB_FREQ, value);
+ i = value & 0x3;
+
+ BUG_ON(i > BYT_BCLK_FREQS);
+
+ return byt_freq_table[i] * 100;
+}
+
static void byt_get_vid(struct cpudata *cpudata)
{
u64 value;
@@ -478,6 +496,11 @@ static int core_get_turbo_pstate(void)
return ret;
}
+static inline int core_get_scaling(void)
+{
+ return 100000;
+}
+
static void core_set_pstate(struct cpudata *cpudata, int pstate)
{
u64 val;
@@ -502,6 +525,7 @@ static struct cpu_defaults core_params =
.get_max = core_get_max_pstate,
.get_min = core_get_min_pstate,
.get_turbo = core_get_turbo_pstate,
+ .get_scaling = core_get_scaling,
.set = core_set_pstate,
},
};
@@ -520,6 +544,7 @@ static struct cpu_defaults byt_params =
.get_min = byt_get_min_pstate,
.get_turbo = byt_get_turbo_pstate,
.set = byt_set_pstate,
+ .get_scaling = byt_get_scaling,
.get_vid = byt_get_vid,
},
};
@@ -554,7 +579,7 @@ static void intel_pstate_set_pstate(stru
if (pstate == cpu->pstate.current_pstate)
return;
- trace_cpu_frequency(pstate * 100000, cpu->cpu);
+ trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
cpu->pstate.current_pstate = pstate;
@@ -566,6 +591,7 @@ static void intel_pstate_get_cpu_pstates
cpu->pstate.min_pstate = pstate_funcs.get_min();
cpu->pstate.max_pstate = pstate_funcs.get_max();
cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
+ cpu->pstate.scaling = pstate_funcs.get_scaling();
if (pstate_funcs.get_vid)
pstate_funcs.get_vid(cpu);
@@ -581,7 +607,9 @@ static inline void intel_pstate_calc_bus
core_pct = div64_u64(core_pct, int_tofp(sample->mperf));
sample->freq = fp_toint(
- mul_fp(int_tofp(cpu->pstate.max_pstate * 1000), core_pct));
+ mul_fp(int_tofp(
+ cpu->pstate.max_pstate * cpu->pstate.scaling / 100),
+ core_pct));
sample->core_pct_busy = (int32_t)core_pct;
}
@@ -803,12 +831,13 @@ static int intel_pstate_cpu_init(struct
else
policy->policy = CPUFREQ_POLICY_POWERSAVE;
- policy->min = cpu->pstate.min_pstate * 100000;
- policy->max = cpu->pstate.turbo_pstate * 100000;
+ policy->min = cpu->pstate.min_pstate * cpu->pstate.scaling;
+ policy->max = cpu->pstate.turbo_pstate * cpu->pstate.scaling;
/* cpuinfo and default policy values */
- policy->cpuinfo.min_freq = cpu->pstate.min_pstate * 100000;
- policy->cpuinfo.max_freq = cpu->pstate.turbo_pstate * 100000;
+ policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
+ policy->cpuinfo.max_freq =
+ cpu->pstate.turbo_pstate * cpu->pstate.scaling;
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
cpumask_set_cpu(policy->cpu, policy->cpus);
@@ -866,6 +895,7 @@ static void copy_cpu_funcs(struct pstate
pstate_funcs.get_max = funcs->get_max;
pstate_funcs.get_min = funcs->get_min;
pstate_funcs.get_turbo = funcs->get_turbo;
+ pstate_funcs.get_scaling = funcs->get_scaling;
pstate_funcs.set = funcs->set;
pstate_funcs.get_vid = funcs->get_vid;
}
Patches currently in stable-queue which might be from dirk.j.brandewie@xxxxxxxxx are
queue-3.17/intel_pstate-fix-byt-frequency-reporting.patch
queue-3.17/cpufreq-expose-scaling_cur_freq-sysfs-file-for-set_policy-drivers.patch
queue-3.17/intel_pstate-don-t-lose-sysfs-settings-during-cpu-offline.patch
queue-3.17/cpufreq-intel_pstate-fix-setting-max_perf_pct-in-performance-policy.patch
queue-3.17/cpufreq-intel_pstate-reflect-current-no_turbo-state-correctly.patch
queue-3.17/intel_pstate-correct-byt-vid-values.patch
--
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