From fe829ed8ef1f3c7ac22843bd594ef2f6c4044288 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Wed, 19 Jul 2017 15:42:48 +0530 Subject: [PATCH] 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 Reviewed-by: Dominik Brodowski Signed-off-by: Rafael J. Wysocki --- 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 88139e5e87da..6ec589c048b2 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2005,11 +2005,12 @@ 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); -- 2.20.1