[PATCH 4/5] intel_pstate: Remove C0 tracking

dirk.brandewie
2014-05-08T19:58:17Z

From: Dirk Brandewie <dirk.j.brandewie@intel.com>

Commit fcb6a15c intel_pstate: Take core C0 time into account for core busy
introduced a regression referenced below. The issue with "lockup"
after suspend that this commit was addressing is now dealt with in the
suspend path.

References:
https://bugzilla.kernel.org/show_bug.cgi?id=66581
https://bugzilla.kernel.org/show_bug.cgi?id=75121

Reported-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
---
drivers/cpufreq/intel_pstate.c | 13 +------------
1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index bb20881..4c26faf 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -59,7 +59,6 @@ struct sample {
int32_t core_pct_busy;
u64 aperf;
u64 mperf;
- unsigned long long tsc;
int freq;
};

@@ -100,7 +99,6 @@ struct cpudata {

u64 prev_aperf;
u64 prev_mperf;
- unsigned long long prev_tsc;
struct sample sample;
};

@@ -561,46 +559,37 @@ static inline void intel_pstate_calc_busy(struct cpudata *cpu,
struct sample *sample)
{
int32_t core_pct;
- int32_t c0_pct;

core_pct = div_fp(int_tofp((sample->aperf)),
int_tofp((sample->mperf)));
core_pct = mul_fp(core_pct, int_tofp(100));
FP_ROUNDUP(core_pct);

- c0_pct = div_fp(int_tofp(sample->mperf), int_tofp(sample->tsc));
-
sample->freq = fp_toint(
mul_fp(int_tofp(cpu->pstate.max_pstate * 1000), core_pct));

- sample->core_pct_busy = mul_fp(core_pct, c0_pct);
+ sample->core_pct_busy = core_pct;
}

static inline void intel_pstate_sample(struct cpudata *cpu)
{
u64 aperf, mperf;
- unsigned long long tsc;

rdmsrl(MSR_IA32_APERF, aperf);
rdmsrl(MSR_IA32_MPERF, mperf);
- tsc = native_read_tsc();

aperf = aperf >> FRAC_BITS;
mperf = mperf >> FRAC_BITS;
- tsc = tsc >> FRAC_BITS;

cpu->sample.aperf = aperf;
cpu->sample.mperf = mperf;
- cpu->sample.tsc = tsc;
cpu->sample.aperf -= cpu->prev_aperf;
cpu->sample.mperf -= cpu->prev_mperf;
- cpu->sample.tsc -= cpu->prev_tsc;

intel_pstate_calc_busy(cpu, &cpu->sample);

cpu->prev_aperf = aperf;
cpu->prev_mperf = mperf;
- cpu->prev_tsc = tsc;
}

static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
--
1.9.0