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Date: Wed, 19 Jul 2017 15:42:48 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Rafael Wysocki <rjw@...ysocki.net>,
Viresh Kumar <viresh.kumar@...aro.org>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Michael Ellerman <mpe@...erman.id.au>
Cc: linux-pm@...r.kernel.org,
Vincent Guittot <vincent.guittot@...aro.org>,
linux@...inikbrodowski.net, linux-kernel@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH V3 8/9] cpufreq: Add CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING cpufreq driver flag
The policy->transition_latency field is used for multiple purposes
today and its not straight forward at all. This is how it is used:
A. Set the correct transition_latency value.
B. Set it to CPUFREQ_ETERNAL because:
1. We don't want automatic dynamic switching (with
ondemand/conservative) to happen at all.
2. We don't know the transition latency.
This patch handles the B.1. case in a more readable way. A new flag for
the cpufreq drivers is added to disallow use of cpufreq governors which
have dynamic_switching flag set.
All the current cpufreq drivers which are setting transition_latency
unconditionally to CPUFREQ_ETERNAL are updated to use it. They don't
need to set transition_latency anymore.
There shouldn't be any functional change after this patch.
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
drivers/cpufreq/cpufreq-nforce2.c | 2 +-
drivers/cpufreq/cpufreq.c | 5 +++--
drivers/cpufreq/elanfreq.c | 4 +---
drivers/cpufreq/gx-suspmod.c | 2 +-
drivers/cpufreq/pmac32-cpufreq.c | 7 +++++--
drivers/cpufreq/sa1100-cpufreq.c | 5 +++--
drivers/cpufreq/sa1110-cpufreq.c | 5 +++--
drivers/cpufreq/sh-cpufreq.c | 3 +--
drivers/cpufreq/speedstep-smi.c | 2 +-
drivers/cpufreq/unicore2-cpufreq.c | 3 +--
include/linux/cpufreq.h | 6 ++++++
11 files changed, 26 insertions(+), 18 deletions(-)
diff --git a/drivers/cpufreq/cpufreq-nforce2.c b/drivers/cpufreq/cpufreq-nforce2.c
index 5503d491b016..dbf82f36d270 100644
--- a/drivers/cpufreq/cpufreq-nforce2.c
+++ b/drivers/cpufreq/cpufreq-nforce2.c
@@ -357,7 +357,6 @@ static int nforce2_cpu_init(struct cpufreq_policy *policy)
/* cpuinfo and default policy values */
policy->min = policy->cpuinfo.min_freq = min_fsb * fid * 100;
policy->max = policy->cpuinfo.max_freq = max_fsb * fid * 100;
- policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
return 0;
}
@@ -369,6 +368,7 @@ static int nforce2_cpu_exit(struct cpufreq_policy *policy)
static struct cpufreq_driver nforce2_driver = {
.name = "nforce2",
+ .flags = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.verify = nforce2_verify,
.target = nforce2_target,
.get = nforce2_get,
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2debfb5f9126..a4d9b47c4af4 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2016,11 +2016,12 @@ static int cpufreq_init_governor(struct cpufreq_policy *policy)
/* Platform doesn't want dynamic frequency switching ? */
if (policy->governor->dynamic_switching &&
- policy->cpuinfo.transition_latency == CPUFREQ_ETERNAL) {
+ (cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING ||
+ policy->cpuinfo.transition_latency == CPUFREQ_ETERNAL)) {
struct cpufreq_governor *gov = cpufreq_fallback_governor();
if (gov) {
- pr_warn("Transition latency set to CPUFREQ_ETERNAL, can't use %s governor. Fallback to %s governor\n",
+ pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
policy->governor->name, gov->name);
policy->governor = gov;
} else {
diff --git a/drivers/cpufreq/elanfreq.c b/drivers/cpufreq/elanfreq.c
index bfce11cba1df..45e2ca62515e 100644
--- a/drivers/cpufreq/elanfreq.c
+++ b/drivers/cpufreq/elanfreq.c
@@ -165,9 +165,6 @@ static int elanfreq_cpu_init(struct cpufreq_policy *policy)
if (pos->frequency > max_freq)
pos->frequency = CPUFREQ_ENTRY_INVALID;
- /* cpuinfo and default policy values */
- policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
-
return cpufreq_table_validate_and_show(policy, elanfreq_table);
}
@@ -196,6 +193,7 @@ __setup("elanfreq=", elanfreq_setup);
static struct cpufreq_driver elanfreq_driver = {
.get = elanfreq_get_cpu_frequency,
+ .flags = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = elanfreq_target,
.init = elanfreq_cpu_init,
diff --git a/drivers/cpufreq/gx-suspmod.c b/drivers/cpufreq/gx-suspmod.c
index 3488c9c175eb..8f52a06664e3 100644
--- a/drivers/cpufreq/gx-suspmod.c
+++ b/drivers/cpufreq/gx-suspmod.c
@@ -428,7 +428,6 @@ static int cpufreq_gx_cpu_init(struct cpufreq_policy *policy)
policy->max = maxfreq;
policy->cpuinfo.min_freq = maxfreq / max_duration;
policy->cpuinfo.max_freq = maxfreq;
- policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
return 0;
}
@@ -438,6 +437,7 @@ static int cpufreq_gx_cpu_init(struct cpufreq_policy *policy)
* MediaGX/Geode GX initialize cpufreq driver
*/
static struct cpufreq_driver gx_suspmod_driver = {
+ .flags = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.get = gx_get_cpuspeed,
.verify = cpufreq_gx_verify,
.target = cpufreq_gx_target,
diff --git a/drivers/cpufreq/pmac32-cpufreq.c b/drivers/cpufreq/pmac32-cpufreq.c
index ff44016ea031..61ae06ca008e 100644
--- a/drivers/cpufreq/pmac32-cpufreq.c
+++ b/drivers/cpufreq/pmac32-cpufreq.c
@@ -442,7 +442,8 @@ static struct cpufreq_driver pmac_cpufreq_driver = {
.init = pmac_cpufreq_cpu_init,
.suspend = pmac_cpufreq_suspend,
.resume = pmac_cpufreq_resume,
- .flags = CPUFREQ_PM_NO_WARN,
+ .flags = CPUFREQ_PM_NO_WARN |
+ CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.attr = cpufreq_generic_attr,
.name = "powermac",
};
@@ -626,14 +627,16 @@ static int __init pmac_cpufreq_setup(void)
if (!value)
goto out;
cur_freq = (*value) / 1000;
- transition_latency = CPUFREQ_ETERNAL;
/* Check for 7447A based MacRISC3 */
if (of_machine_is_compatible("MacRISC3") &&
of_get_property(cpunode, "dynamic-power-step", NULL) &&
PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
pmac_cpufreq_init_7447A(cpunode);
+
+ /* Allow dynamic switching */
transition_latency = 8000000;
+ pmac_cpufreq_driver.flags &= ~CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
/* Check for other MacRISC3 machines */
} else if (of_machine_is_compatible("PowerBook3,4") ||
of_machine_is_compatible("PowerBook3,5") ||
diff --git a/drivers/cpufreq/sa1100-cpufreq.c b/drivers/cpufreq/sa1100-cpufreq.c
index 728eab77e8e0..e2d8a77c36d5 100644
--- a/drivers/cpufreq/sa1100-cpufreq.c
+++ b/drivers/cpufreq/sa1100-cpufreq.c
@@ -197,11 +197,12 @@ static int sa1100_target(struct cpufreq_policy *policy, unsigned int ppcr)
static int __init sa1100_cpu_init(struct cpufreq_policy *policy)
{
- return cpufreq_generic_init(policy, sa11x0_freq_table, CPUFREQ_ETERNAL);
+ return cpufreq_generic_init(policy, sa11x0_freq_table, 0);
}
static struct cpufreq_driver sa1100_driver __refdata = {
- .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+ .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK |
+ CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = sa1100_target,
.get = sa11x0_getspeed,
diff --git a/drivers/cpufreq/sa1110-cpufreq.c b/drivers/cpufreq/sa1110-cpufreq.c
index 2bac9b6cfeea..66e5fb088ecc 100644
--- a/drivers/cpufreq/sa1110-cpufreq.c
+++ b/drivers/cpufreq/sa1110-cpufreq.c
@@ -306,13 +306,14 @@ static int sa1110_target(struct cpufreq_policy *policy, unsigned int ppcr)
static int __init sa1110_cpu_init(struct cpufreq_policy *policy)
{
- return cpufreq_generic_init(policy, sa11x0_freq_table, CPUFREQ_ETERNAL);
+ return cpufreq_generic_init(policy, sa11x0_freq_table, 0);
}
/* sa1110_driver needs __refdata because it must remain after init registers
* it with cpufreq_register_driver() */
static struct cpufreq_driver sa1110_driver __refdata = {
- .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+ .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK |
+ CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = sa1110_target,
.get = sa11x0_getspeed,
diff --git a/drivers/cpufreq/sh-cpufreq.c b/drivers/cpufreq/sh-cpufreq.c
index 719c3d9f07fb..28893d435cf5 100644
--- a/drivers/cpufreq/sh-cpufreq.c
+++ b/drivers/cpufreq/sh-cpufreq.c
@@ -137,8 +137,6 @@ static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy)
(clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
}
- policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
-
dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, "
"Maximum %u.%03u MHz.\n",
policy->min / 1000, policy->min % 1000,
@@ -159,6 +157,7 @@ static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy)
static struct cpufreq_driver sh_cpufreq_driver = {
.name = "sh",
+ .flags = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.get = sh_cpufreq_get,
.target = sh_cpufreq_target,
.verify = sh_cpufreq_verify,
diff --git a/drivers/cpufreq/speedstep-smi.c b/drivers/cpufreq/speedstep-smi.c
index 37b30071c220..d23f24ccff38 100644
--- a/drivers/cpufreq/speedstep-smi.c
+++ b/drivers/cpufreq/speedstep-smi.c
@@ -266,7 +266,6 @@ static int speedstep_cpu_init(struct cpufreq_policy *policy)
pr_debug("workaround worked.\n");
}
- policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
return cpufreq_table_validate_and_show(policy, speedstep_freqs);
}
@@ -290,6 +289,7 @@ static int speedstep_resume(struct cpufreq_policy *policy)
static struct cpufreq_driver speedstep_driver = {
.name = "speedstep-smi",
+ .flags = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = speedstep_target,
.init = speedstep_cpu_init,
diff --git a/drivers/cpufreq/unicore2-cpufreq.c b/drivers/cpufreq/unicore2-cpufreq.c
index 6f9dfa80563a..db62d9844751 100644
--- a/drivers/cpufreq/unicore2-cpufreq.c
+++ b/drivers/cpufreq/unicore2-cpufreq.c
@@ -58,13 +58,12 @@ static int __init ucv2_cpu_init(struct cpufreq_policy *policy)
policy->min = policy->cpuinfo.min_freq = 250000;
policy->max = policy->cpuinfo.max_freq = 1000000;
- policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
policy->clk = clk_get(NULL, "MAIN_CLK");
return PTR_ERR_OR_ZERO(policy->clk);
}
static struct cpufreq_driver ucv2_driver = {
- .flags = CPUFREQ_STICKY,
+ .flags = CPUFREQ_STICKY | CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
.verify = ucv2_verify_speed,
.target = ucv2_target,
.get = cpufreq_generic_get,
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index e141dbbb9d1c..5f40522ec98c 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -370,6 +370,12 @@ struct cpufreq_driver {
*/
#define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
+/*
+ * Set by drivers to disallow use of governors with "dynamic_switching" flag
+ * set.
+ */
+#define CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING (1 << 6)
+
int cpufreq_register_driver(struct cpufreq_driver *driver_data);
int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
--
2.13.0.71.gd7076ec9c9cb
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