[PATCH 02/14] cpufreq: intel_pstate: Drop pointless initialization of PID parameters

From: Rafael J. Wysocki
Date: Sun Mar 12 2017 - 13:33:15 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

The P-state selection algorithm used by intel_pstate for Atom
processors is not based on the PID controller and the initialization
of PID parametrs for those processors is pointless and confusing, so
drop it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 28 ++--------------------------
1 file changed, 2 insertions(+), 26 deletions(-)

Index: linux-pm/drivers/cpufreq/intel_pstate.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/intel_pstate.c
+++ linux-pm/drivers/cpufreq/intel_pstate.c
@@ -1592,14 +1592,6 @@ static struct cpu_defaults core_params =
};

static const struct cpu_defaults silvermont_params = {
- .pid_policy = {
- .sample_rate_ms = 10,
- .deadband = 0,
- .setpoint = 60,
- .p_gain_pct = 14,
- .d_gain_pct = 0,
- .i_gain_pct = 4,
- },
.funcs = {
.get_max = atom_get_max_pstate,
.get_max_physical = atom_get_max_pstate,
@@ -1613,14 +1605,6 @@ static const struct cpu_defaults silverm
};

static const struct cpu_defaults airmont_params = {
- .pid_policy = {
- .sample_rate_ms = 10,
- .deadband = 0,
- .setpoint = 60,
- .p_gain_pct = 14,
- .d_gain_pct = 0,
- .i_gain_pct = 4,
- },
.funcs = {
.get_max = atom_get_max_pstate,
.get_max_physical = atom_get_max_pstate,
@@ -1654,14 +1638,6 @@ static const struct cpu_defaults knl_par
};

static const struct cpu_defaults bxt_params = {
- .pid_policy = {
- .sample_rate_ms = 10,
- .deadband = 0,
- .setpoint = 60,
- .p_gain_pct = 14,
- .d_gain_pct = 0,
- .i_gain_pct = 4,
- },
.funcs = {
.get_max = core_get_max_pstate,
.get_max_physical = core_get_max_pstate_physical,
@@ -2721,9 +2697,9 @@ static int __init intel_pstate_init(void
return -ENODEV;

cpu_def = (struct cpu_defaults *)id->driver_data;
-
- copy_pid_params(&cpu_def->pid_policy);
copy_cpu_funcs(&cpu_def->funcs);
+ if (pstate_funcs.get_target_pstate == get_target_pstate_use_performance)
+ copy_pid_params(&cpu_def->pid_policy);

if (intel_pstate_msrs_not_valid())
return -ENODEV;