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Message-Id: <20211210163141.213106-2-chetan.mistry@arm.com>
Date: Fri, 10 Dec 2021 16:31:41 +0000
From: Chetankumar Mistry <chetan.mistry@....com>
To: linux-kernel@...r.kernel.org
Cc: lukasz.luba@....com, rafael@...nel.org, daniel.lezcano@...aro.org,
amitk@...nel.org, rui.zhang@...el.com, linux-pm@...r.kernel.org
Subject: [PATCH][RFC 2/2] Remove sysfs entry
The previous patch introduced a sysfs entry to track the
Ziegler-Nichols state.
This patch will remove it, if it is unwanted.
Signed-off-by: Chetankumar Mistry <chetan.mistry@....com>
---
drivers/thermal/gov_power_allocator.c | 68 ++++++++++++++++++---------
drivers/thermal/thermal_sysfs.c | 2 -
include/linux/thermal.h | 7 ---
3 files changed, 45 insertions(+), 32 deletions(-)
diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
index 7819c693ed1a..5be0dfb5f7fc 100644
--- a/drivers/thermal/gov_power_allocator.c
+++ b/drivers/thermal/gov_power_allocator.c
@@ -99,6 +99,8 @@ struct zn_coefficients {
s32 base_trough;
s32 oscillation_count;
enum pivot_type prev_pivot;
+
+ int zn_state;
};
/**
@@ -420,7 +422,31 @@ static inline s32 get_oscillation_count(s32 curr_err,
zn_coeffs);
}
-/** is_temperature_safe() - Check if the current temperature is within 10% of the target
+/**
+ * get_zn_state() - Update and get the current Ziegler-Nichols State
+ * @tzp - The thermal zone params to check to determine the current state
+ * @zn_state - The current state which should be returned if no changes are
+ * made
+ *
+ * Return: The next zieger-nichols state for this pass of the PID controller
+ */
+static inline int get_zn_state(struct thermal_zone_params *tzp, int zn_state)
+{
+ if (tzp->k_po == ZN_RESET && tzp->k_pu == ZN_RESET)
+ return ZN_RESET;
+
+ if (tzp->k_po == ZN_ORIGINAL && tzp->k_pu == ZN_ORIGINAL)
+ return ZN_ORIGINAL;
+
+ if (tzp->k_po == ZN_ON && tzp->k_pu == ZN_ON)
+ return ZN_ON;
+
+ return zn_state;
+}
+
+/**
+ * is_temperature_safe() - Check if the current temperature is within 10% of
+ * the target
*
* @current_temperature: Current reported temperature
* @control_temp: Control Temperature we are targeting
@@ -481,9 +507,21 @@ static inline void ziegler_nichols(struct thermal_zone_device *tz, s32 next_err,
bool is_safe =
is_temperature_safe((control_temp - next_err), control_temp);
- if (tz->tzp->ziegler_nichols == ZN_RESET) {
+ zn_coeffs->zn_state = get_zn_state(tz->tzp, zn_coeffs->zn_state);
+ switch (zn_coeffs->zn_state) {
+ case ZN_ORIGINAL: {
+ set_original_pid_coefficients(tz->tzp);
+ zn_coeffs->zn_state = ZN_OFF;
+ return;
+ }
+ case ZN_RESET: {
reset_ziegler_nichols(zn_coeffs);
- tz->tzp->ziegler_nichols = ZN_ON;
+ zn_coeffs->zn_state = ZN_ON;
+ break;
+ }
+
+ case ZN_OFF:
+ return;
}
/* Override default PID Coefficients. These will be updated later according to the
@@ -523,7 +561,7 @@ static inline void ziegler_nichols(struct thermal_zone_device *tz, s32 next_err,
} else {
set_zn_pid_coefficients(tz->tzp, zn_coeffs->period,
zn_coeffs->k_ultimate);
- tz->tzp->ziegler_nichols = ZN_OFF;
+ zn_coeffs->zn_state = ZN_OFF;
}
return;
@@ -540,7 +578,7 @@ static inline void ziegler_nichols(struct thermal_zone_device *tz, s32 next_err,
zn_coeffs->k_ultimate);
((struct power_allocator_params *)tz->governor_data)
->err_integral = 0;
- tz->tzp->ziegler_nichols = ZN_OFF;
+ zn_coeffs->zn_state = ZN_OFF;
} else {
if (peak_trough == PEAK)
zn_coeffs->t_prev_peak = t_now;
@@ -580,24 +618,7 @@ static u32 pid_controller(struct thermal_zone_device *tz,
err = control_temp - tz->temperature;
- switch (tz->tzp->ziegler_nichols) {
- case ZN_ORIGINAL: {
- set_original_pid_coefficients(tz->tzp);
- tz->tzp->ziegler_nichols = ZN_OFF;
- break;
- }
- case ZN_RESET: {
- ziegler_nichols(tz, err, control_temp);
- tz->tzp->ziegler_nichols = ZN_ON;
- break;
- }
- case ZN_ON: {
- ziegler_nichols(tz, err, control_temp);
- break;
- }
- default:
- break;
- }
+ ziegler_nichols(tz, err, control_temp);
err = int_to_frac(err);
@@ -1031,6 +1052,7 @@ static int power_allocator_bind(struct thermal_zone_device *tz)
return -ENOMEM;
params->zn_coeffs = zn_coeffs;
+ zn_coeffs->zn_state = ZN_ON;
if (!tz->tzp) {
tz->tzp = kzalloc(sizeof(*tz->tzp), GFP_KERNEL);
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index d2f410a33995..f154bada2906 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -342,7 +342,6 @@ create_s32_tzp_attr(k_po);
create_s32_tzp_attr(k_pu);
create_s32_tzp_attr(k_i);
create_s32_tzp_attr(k_d);
-create_s32_tzp_attr(ziegler_nichols);
create_s32_tzp_attr(integral_cutoff);
create_s32_tzp_attr(slope);
create_s32_tzp_attr(offset);
@@ -376,7 +375,6 @@ static struct attribute *thermal_zone_dev_attrs[] = {
&dev_attr_k_pu.attr,
&dev_attr_k_i.attr,
&dev_attr_k_d.attr,
- &dev_attr_ziegler_nichols.attr,
&dev_attr_integral_cutoff.attr,
&dev_attr_slope.attr,
&dev_attr_offset.attr,
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index ed8cd6a826ed..c314893970b3 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -282,13 +282,6 @@ struct thermal_zone_params {
* Used by thermal zone drivers (default 0).
*/
int offset;
-
- /*
- * Ziegler-Nichols estimation setting. Allows the user to decide
- * whether to use original PID coefficients or calculate using
- * the Ziegler-Nichols algorithm
- */
- s32 ziegler_nichols;
};
/**
--
2.25.1
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