From: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx> This patch does NOT apply to the 3.12 stable tree. If you still want it applied, please provide a backport. =============== 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 Cc: All applicable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- drivers/cpufreq/intel_pstate.c | 42 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 36 insertions(+), 6 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 97b349a6f5c7..98593e0344c5 100644 --- 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 cpudata *cpudata, int pstate) 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(struct cpudata *cpu, int pstate) 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(struct cpudata *cpu) 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_busy(struct cpudata *cpu) 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 cpufreq_policy *policy) 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_funcs *funcs) 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; } -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html