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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2025-10-07 12:31:46 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2025-10-07 12:31:46 +0200
commit53d4d315d4f7f17882ef11db49b06ca6b0be8ff7 (patch)
treebd8709a0b5379a74a6f07c92e514511a49a3e60e
parent05f084d24e098d93c7b0803e32b9be9fff6ef490 (diff)
parent7e8f305a081e22ce81aab7f7b9ce01437cbd38b3 (diff)
Merge branch 'pm-cpufreq'
Merge cpufreq fixes and cleanups, mostly on top of those fixes, for 6.18-rc1: - Make cpufreq drivers setting the default CPU transition latency to CPUFREQ_ETERNAL specify a proper default transition latency value instead which addresses a regression introduced during the 6.6 cycle that broke CPUFREQ_ETERNAL handling (Rafael Wysocki) - Make the cpufreq CPPC driver use a proper transition delay value when CPUFREQ_ETERNAL is returned by cppc_get_transition_latency() to indicate an error condition (Rafael Wysocki) - Make cppc_get_transition_latency() return a negative error code to indicate error conditions instead of using CPUFREQ_ETERNAL for this purpose and drop CPUFREQ_ETERNAL that has no other users (Rafael Wysocki, Gopi Krishna Menon) - Fix device leak in the mediatek cpufreq driver (Johan Hovold) - Set target frequency on all CPUs sharing a policy during frequency updates in the tegra186 cpufreq driver and make it initialize all cores to max frequencies (Aaron Kling) - Rust cpufreq helper cleanup (Thorsten Blum) * pm-cpufreq: docs/zh_CN: Fix malformed table docs/zh_TW: Fix malformed table cpufreq: Drop unused symbol CPUFREQ_ETERNAL ACPI: CPPC: Do not use CPUFREQ_ETERNAL as an error value cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency cpufreq: tegra186: Initialize all cores to max frequencies cpufreq: tegra186: Set target frequency for all cpus in policy rust: cpufreq: streamline find_supply_names cpufreq: mediatek: fix device leak on probe failure
-rw-r--r--Documentation/admin-guide/pm/cpufreq.rst4
-rw-r--r--Documentation/cpu-freq/cpu-drivers.rst3
-rw-r--r--Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst3
-rw-r--r--Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst3
-rw-r--r--drivers/acpi/cppc_acpi.c16
-rw-r--r--drivers/cpufreq/amd-pstate.c8
-rw-r--r--drivers/cpufreq/cppc_cpufreq.c14
-rw-r--r--drivers/cpufreq/cpufreq-dt.c2
-rw-r--r--drivers/cpufreq/imx6q-cpufreq.c2
-rw-r--r--drivers/cpufreq/mediatek-cpufreq-hw.c2
-rw-r--r--drivers/cpufreq/mediatek-cpufreq.c14
-rw-r--r--drivers/cpufreq/rcpufreq_dt.rs12
-rw-r--r--drivers/cpufreq/scmi-cpufreq.c2
-rw-r--r--drivers/cpufreq/scpi-cpufreq.c2
-rw-r--r--drivers/cpufreq/spear-cpufreq.c2
-rw-r--r--drivers/cpufreq/tegra186-cpufreq.c35
-rw-r--r--include/acpi/cppc_acpi.h6
-rw-r--r--include/linux/cpufreq.h6
-rw-r--r--rust/kernel/cpufreq.rs7
19 files changed, 83 insertions, 60 deletions
diff --git a/Documentation/admin-guide/pm/cpufreq.rst b/Documentation/admin-guide/pm/cpufreq.rst
index cacb9f0307dd..738d7b4dc33a 100644
--- a/Documentation/admin-guide/pm/cpufreq.rst
+++ b/Documentation/admin-guide/pm/cpufreq.rst
@@ -274,10 +274,6 @@ are the following:
The time it takes to switch the CPUs belonging to this policy from one
P-state to another, in nanoseconds.
- If unknown or if known to be so high that the scaling driver does not
- work with the `ondemand`_ governor, -1 (:c:macro:`CPUFREQ_ETERNAL`)
- will be returned by reads from this attribute.
-
``related_cpus``
List of all (online and offline) CPUs belonging to this policy.
diff --git a/Documentation/cpu-freq/cpu-drivers.rst b/Documentation/cpu-freq/cpu-drivers.rst
index d84ededb66f9..c5635ac3de54 100644
--- a/Documentation/cpu-freq/cpu-drivers.rst
+++ b/Documentation/cpu-freq/cpu-drivers.rst
@@ -109,8 +109,7 @@ Then, the driver must fill in the following values:
+-----------------------------------+--------------------------------------+
|policy->cpuinfo.transition_latency | the time it takes on this CPU to |
| | switch between two frequencies in |
-| | nanoseconds (if appropriate, else |
-| | specify CPUFREQ_ETERNAL) |
+| | nanoseconds |
+-----------------------------------+--------------------------------------+
|policy->cur | The current operating frequency of |
| | this CPU (if appropriate) |
diff --git a/Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst b/Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst
index 2ca92042767b..2d5e84d8e58d 100644
--- a/Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst
+++ b/Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst
@@ -112,8 +112,7 @@ CPUfreq核心层注册一个cpufreq_driver结构体。
| | |
+-----------------------------------+--------------------------------------+
|policy->cpuinfo.transition_latency | CPU在两个频率之间切换所需的时间,以 |
-| | 纳秒为单位(如不适用,设定为 |
-| | CPUFREQ_ETERNAL) |
+| | 纳秒为单位 |
| | |
+-----------------------------------+--------------------------------------+
|policy->cur | 该CPU当前的工作频率(如适用) |
diff --git a/Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst b/Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst
index add3de2d4523..7f751a7add56 100644
--- a/Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst
+++ b/Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst
@@ -112,8 +112,7 @@ CPUfreq核心層註冊一個cpufreq_driver結構體。
| | |
+-----------------------------------+--------------------------------------+
|policy->cpuinfo.transition_latency | CPU在兩個頻率之間切換所需的時間,以 |
-| | 納秒爲單位(如不適用,設定爲 |
-| | CPUFREQ_ETERNAL) |
+| | 納秒爲單位 |
| | |
+-----------------------------------+--------------------------------------+
|policy->cur | 該CPU當前的工作頻率(如適用) |
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 6b649031808f..ab4651205e8a 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1876,7 +1876,7 @@ EXPORT_SYMBOL_GPL(cppc_set_perf);
* If desired_reg is in the SystemMemory or SystemIo ACPI address space,
* then assume there is no latency.
*/
-unsigned int cppc_get_transition_latency(int cpu_num)
+int cppc_get_transition_latency(int cpu_num)
{
/*
* Expected transition latency is based on the PCCT timing values
@@ -1889,31 +1889,29 @@ unsigned int cppc_get_transition_latency(int cpu_num)
* completion of a command before issuing the next command,
* in microseconds.
*/
- unsigned int latency_ns = 0;
struct cpc_desc *cpc_desc;
struct cpc_register_resource *desired_reg;
int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu_num);
struct cppc_pcc_data *pcc_ss_data;
+ int latency_ns = 0;
cpc_desc = per_cpu(cpc_desc_ptr, cpu_num);
if (!cpc_desc)
- return CPUFREQ_ETERNAL;
+ return -ENODATA;
desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF];
if (CPC_IN_SYSTEM_MEMORY(desired_reg) || CPC_IN_SYSTEM_IO(desired_reg))
return 0;
- else if (!CPC_IN_PCC(desired_reg))
- return CPUFREQ_ETERNAL;
- if (pcc_ss_id < 0)
- return CPUFREQ_ETERNAL;
+ if (!CPC_IN_PCC(desired_reg) || pcc_ss_id < 0)
+ return -ENODATA;
pcc_ss_data = pcc_data[pcc_ss_id];
if (pcc_ss_data->pcc_mpar)
latency_ns = 60 * (1000 * 1000 * 1000 / pcc_ss_data->pcc_mpar);
- latency_ns = max(latency_ns, pcc_ss_data->pcc_nominal * 1000);
- latency_ns = max(latency_ns, pcc_ss_data->pcc_mrtt * 1000);
+ latency_ns = max_t(int, latency_ns, pcc_ss_data->pcc_nominal * 1000);
+ latency_ns = max_t(int, latency_ns, pcc_ss_data->pcc_mrtt * 1000);
return latency_ns;
}
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index b4c79fde1979..298e92d8cc03 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -872,10 +872,10 @@ static void amd_pstate_update_limits(struct cpufreq_policy *policy)
*/
static u32 amd_pstate_get_transition_delay_us(unsigned int cpu)
{
- u32 transition_delay_ns;
+ int transition_delay_ns;
transition_delay_ns = cppc_get_transition_latency(cpu);
- if (transition_delay_ns == CPUFREQ_ETERNAL) {
+ if (transition_delay_ns < 0) {
if (cpu_feature_enabled(X86_FEATURE_AMD_FAST_CPPC))
return AMD_PSTATE_FAST_CPPC_TRANSITION_DELAY;
else
@@ -891,10 +891,10 @@ static u32 amd_pstate_get_transition_delay_us(unsigned int cpu)
*/
static u32 amd_pstate_get_transition_latency(unsigned int cpu)
{
- u32 transition_latency;
+ int transition_latency;
transition_latency = cppc_get_transition_latency(cpu);
- if (transition_latency == CPUFREQ_ETERNAL)
+ if (transition_latency < 0)
return AMD_PSTATE_TRANSITION_LATENCY;
return transition_latency;
diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 12de0ac7bbaf..e23d9abea135 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -308,6 +308,16 @@ static int cppc_verify_policy(struct cpufreq_policy_data *policy)
return 0;
}
+static unsigned int __cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
+{
+ int transition_latency_ns = cppc_get_transition_latency(cpu);
+
+ if (transition_latency_ns < 0)
+ return CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS / NSEC_PER_USEC;
+
+ return transition_latency_ns / NSEC_PER_USEC;
+}
+
/*
* The PCC subspace describes the rate at which platform can accept commands
* on the shared PCC channel (including READs which do not count towards freq
@@ -330,12 +340,12 @@ static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
return 10000;
}
}
- return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
+ return __cppc_cpufreq_get_transition_delay_us(cpu);
}
#else
static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
{
- return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
+ return __cppc_cpufreq_get_transition_delay_us(cpu);
}
#endif
diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index 506437489b4d..7d5079fd1688 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -104,7 +104,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
if (!transition_latency)
- transition_latency = CPUFREQ_ETERNAL;
+ transition_latency = CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS;
cpumask_copy(policy->cpus, priv->cpus);
policy->driver_data = priv;
diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index db1c88e9d3f9..e93697d3edfd 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -442,7 +442,7 @@ soc_opp_out:
}
if (of_property_read_u32(np, "clock-latency", &transition_latency))
- transition_latency = CPUFREQ_ETERNAL;
+ transition_latency = CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS;
/*
* Calculate the ramp time for max voltage change in the
diff --git a/drivers/cpufreq/mediatek-cpufreq-hw.c b/drivers/cpufreq/mediatek-cpufreq-hw.c
index fce5aa5ceea0..ae4500ab4891 100644
--- a/drivers/cpufreq/mediatek-cpufreq-hw.c
+++ b/drivers/cpufreq/mediatek-cpufreq-hw.c
@@ -309,7 +309,7 @@ static int mtk_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
latency = readl_relaxed(data->reg_bases[REG_FREQ_LATENCY]) * 1000;
if (!latency)
- latency = CPUFREQ_ETERNAL;
+ latency = CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS;
policy->cpuinfo.transition_latency = latency;
policy->fast_switch_possible = true;
diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
index 00de1166188a..5d50a231f944 100644
--- a/drivers/cpufreq/mediatek-cpufreq.c
+++ b/drivers/cpufreq/mediatek-cpufreq.c
@@ -403,9 +403,11 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
}
info->cpu_clk = clk_get(cpu_dev, "cpu");
- if (IS_ERR(info->cpu_clk))
- return dev_err_probe(cpu_dev, PTR_ERR(info->cpu_clk),
- "cpu%d: failed to get cpu clk\n", cpu);
+ if (IS_ERR(info->cpu_clk)) {
+ ret = PTR_ERR(info->cpu_clk);
+ dev_err_probe(cpu_dev, ret, "cpu%d: failed to get cpu clk\n", cpu);
+ goto out_put_cci_dev;
+ }
info->inter_clk = clk_get(cpu_dev, "intermediate");
if (IS_ERR(info->inter_clk)) {
@@ -551,6 +553,10 @@ out_free_inter_clock:
out_free_mux_clock:
clk_put(info->cpu_clk);
+out_put_cci_dev:
+ if (info->soc_data->ccifreq_supported)
+ put_device(info->cci_dev);
+
return ret;
}
@@ -568,6 +574,8 @@ static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
clk_put(info->inter_clk);
dev_pm_opp_of_cpumask_remove_table(&info->cpus);
dev_pm_opp_unregister_notifier(info->cpu_dev, &info->opp_nb);
+ if (info->soc_data->ccifreq_supported)
+ put_device(info->cci_dev);
}
static int mtk_cpufreq_init(struct cpufreq_policy *policy)
diff --git a/drivers/cpufreq/rcpufreq_dt.rs b/drivers/cpufreq/rcpufreq_dt.rs
index 7e1fbf9a091f..53923b8ef7a1 100644
--- a/drivers/cpufreq/rcpufreq_dt.rs
+++ b/drivers/cpufreq/rcpufreq_dt.rs
@@ -28,15 +28,11 @@ fn find_supply_name_exact(dev: &Device, name: &str) -> Option<CString> {
/// Finds supply name for the CPU from DT.
fn find_supply_names(dev: &Device, cpu: cpu::CpuId) -> Option<KVec<CString>> {
// Try "cpu0" for older DTs, fallback to "cpu".
- let name = (cpu.as_u32() == 0)
+ (cpu.as_u32() == 0)
.then(|| find_supply_name_exact(dev, "cpu0"))
.flatten()
- .or_else(|| find_supply_name_exact(dev, "cpu"))?;
-
- let mut list = KVec::with_capacity(1, GFP_KERNEL).ok()?;
- list.push(name, GFP_KERNEL).ok()?;
-
- Some(list)
+ .or_else(|| find_supply_name_exact(dev, "cpu"))
+ .and_then(|name| kernel::kvec![name].ok())
}
/// Represents the cpufreq dt device.
@@ -123,7 +119,7 @@ impl cpufreq::Driver for CPUFreqDTDriver {
let mut transition_latency = opp_table.max_transition_latency_ns() as u32;
if transition_latency == 0 {
- transition_latency = cpufreq::ETERNAL_LATENCY_NS;
+ transition_latency = cpufreq::DEFAULT_TRANSITION_LATENCY_NS;
}
policy
diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c
index 38c165d526d1..d2a110079f5f 100644
--- a/drivers/cpufreq/scmi-cpufreq.c
+++ b/drivers/cpufreq/scmi-cpufreq.c
@@ -294,7 +294,7 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
latency = perf_ops->transition_latency_get(ph, domain);
if (!latency)
- latency = CPUFREQ_ETERNAL;
+ latency = CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS;
policy->cpuinfo.transition_latency = latency;
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
index dcbb0ae7dd47..e530345baddf 100644
--- a/drivers/cpufreq/scpi-cpufreq.c
+++ b/drivers/cpufreq/scpi-cpufreq.c
@@ -157,7 +157,7 @@ static int scpi_cpufreq_init(struct cpufreq_policy *policy)
latency = scpi_ops->get_transition_latency(cpu_dev);
if (!latency)
- latency = CPUFREQ_ETERNAL;
+ latency = CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS;
policy->cpuinfo.transition_latency = latency;
diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c
index 707c71090cc3..2a1550e1aa21 100644
--- a/drivers/cpufreq/spear-cpufreq.c
+++ b/drivers/cpufreq/spear-cpufreq.c
@@ -182,7 +182,7 @@ static int spear_cpufreq_probe(struct platform_device *pdev)
if (of_property_read_u32(np, "clock-latency",
&spear_cpufreq.transition_latency))
- spear_cpufreq.transition_latency = CPUFREQ_ETERNAL;
+ spear_cpufreq.transition_latency = CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS;
cnt = of_property_count_u32_elems(np, "cpufreq_tbl");
if (cnt <= 0) {
diff --git a/drivers/cpufreq/tegra186-cpufreq.c b/drivers/cpufreq/tegra186-cpufreq.c
index 4270686fc3e3..136ab102f636 100644
--- a/drivers/cpufreq/tegra186-cpufreq.c
+++ b/drivers/cpufreq/tegra186-cpufreq.c
@@ -93,10 +93,14 @@ static int tegra186_cpufreq_set_target(struct cpufreq_policy *policy,
{
struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
struct cpufreq_frequency_table *tbl = policy->freq_table + index;
- unsigned int edvd_offset = data->cpus[policy->cpu].edvd_offset;
+ unsigned int edvd_offset;
u32 edvd_val = tbl->driver_data;
+ u32 cpu;
- writel(edvd_val, data->regs + edvd_offset);
+ for_each_cpu(cpu, policy->cpus) {
+ edvd_offset = data->cpus[cpu].edvd_offset;
+ writel(edvd_val, data->regs + edvd_offset);
+ }
return 0;
}
@@ -132,13 +136,14 @@ static struct cpufreq_driver tegra186_cpufreq_driver = {
static struct cpufreq_frequency_table *init_vhint_table(
struct platform_device *pdev, struct tegra_bpmp *bpmp,
- struct tegra186_cpufreq_cluster *cluster, unsigned int cluster_id)
+ struct tegra186_cpufreq_cluster *cluster, unsigned int cluster_id,
+ int *num_rates)
{
struct cpufreq_frequency_table *table;
struct mrq_cpu_vhint_request req;
struct tegra_bpmp_message msg;
struct cpu_vhint_data *data;
- int err, i, j, num_rates = 0;
+ int err, i, j;
dma_addr_t phys;
void *virt;
@@ -168,6 +173,7 @@ static struct cpufreq_frequency_table *init_vhint_table(
goto free;
}
+ *num_rates = 0;
for (i = data->vfloor; i <= data->vceil; i++) {
u16 ndiv = data->ndiv[i];
@@ -178,10 +184,10 @@ static struct cpufreq_frequency_table *init_vhint_table(
if (i > 0 && ndiv == data->ndiv[i - 1])
continue;
- num_rates++;
+ (*num_rates)++;
}
- table = devm_kcalloc(&pdev->dev, num_rates + 1, sizeof(*table),
+ table = devm_kcalloc(&pdev->dev, *num_rates + 1, sizeof(*table),
GFP_KERNEL);
if (!table) {
table = ERR_PTR(-ENOMEM);
@@ -223,7 +229,9 @@ static int tegra186_cpufreq_probe(struct platform_device *pdev)
{
struct tegra186_cpufreq_data *data;
struct tegra_bpmp *bpmp;
- unsigned int i = 0, err;
+ unsigned int i = 0, err, edvd_offset;
+ int num_rates = 0;
+ u32 edvd_val, cpu;
data = devm_kzalloc(&pdev->dev,
struct_size(data, clusters, TEGRA186_NUM_CLUSTERS),
@@ -246,10 +254,21 @@ static int tegra186_cpufreq_probe(struct platform_device *pdev)
for (i = 0; i < TEGRA186_NUM_CLUSTERS; i++) {
struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
- cluster->table = init_vhint_table(pdev, bpmp, cluster, i);
+ cluster->table = init_vhint_table(pdev, bpmp, cluster, i, &num_rates);
if (IS_ERR(cluster->table)) {
err = PTR_ERR(cluster->table);
goto put_bpmp;
+ } else if (!num_rates) {
+ err = -EINVAL;
+ goto put_bpmp;
+ }
+
+ for (cpu = 0; cpu < ARRAY_SIZE(tegra186_cpus); cpu++) {
+ if (data->cpus[cpu].bpmp_cluster_id == i) {
+ edvd_val = cluster->table[num_rates - 1].driver_data;
+ edvd_offset = data->cpus[cpu].edvd_offset;
+ writel(edvd_val, data->regs + edvd_offset);
+ }
}
}
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 20f3d62e7a16..13fa81504844 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -160,7 +160,7 @@ extern unsigned int cppc_khz_to_perf(struct cppc_perf_caps *caps, unsigned int f
extern bool acpi_cpc_valid(void);
extern bool cppc_allow_fast_switch(void);
extern int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data);
-extern unsigned int cppc_get_transition_latency(int cpu);
+extern int cppc_get_transition_latency(int cpu);
extern bool cpc_ffh_supported(void);
extern bool cpc_supported_by_cpu(void);
extern int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val);
@@ -216,9 +216,9 @@ static inline bool cppc_allow_fast_switch(void)
{
return false;
}
-static inline unsigned int cppc_get_transition_latency(int cpu)
+static inline int cppc_get_transition_latency(int cpu)
{
- return CPUFREQ_ETERNAL;
+ return -ENODATA;
}
static inline bool cpc_ffh_supported(void)
{
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 40966512ea18..0465d1e6f72a 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -26,12 +26,10 @@
*********************************************************************/
/*
* Frequency values here are CPU kHz
- *
- * Maximum transition latency is in nanoseconds - if it's unknown,
- * CPUFREQ_ETERNAL shall be used.
*/
-#define CPUFREQ_ETERNAL (-1)
+#define CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS NSEC_PER_MSEC
+
#define CPUFREQ_NAME_LEN 16
/* Print length for names. Extra 1 space for accommodating '\n' in prints */
#define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
diff --git a/rust/kernel/cpufreq.rs b/rust/kernel/cpufreq.rs
index 29bdf7fe80a1..21b5b9b8acc1 100644
--- a/rust/kernel/cpufreq.rs
+++ b/rust/kernel/cpufreq.rs
@@ -38,7 +38,8 @@ use macros::vtable;
const CPUFREQ_NAME_LEN: usize = bindings::CPUFREQ_NAME_LEN as usize;
/// Default transition latency value in nanoseconds.
-pub const ETERNAL_LATENCY_NS: u32 = bindings::CPUFREQ_ETERNAL as u32;
+pub const DEFAULT_TRANSITION_LATENCY_NS: u32 =
+ bindings::CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS;
/// CPU frequency driver flags.
pub mod flags {
@@ -399,13 +400,13 @@ impl TableBuilder {
/// The following example demonstrates how to create a CPU frequency table.
///
/// ```
-/// use kernel::cpufreq::{ETERNAL_LATENCY_NS, Policy};
+/// use kernel::cpufreq::{DEFAULT_TRANSITION_LATENCY_NS, Policy};
///
/// fn update_policy(policy: &mut Policy) {
/// policy
/// .set_dvfs_possible_from_any_cpu(true)
/// .set_fast_switch_possible(true)
-/// .set_transition_latency_ns(ETERNAL_LATENCY_NS);
+/// .set_transition_latency_ns(DEFAULT_TRANSITION_LATENCY_NS);
///
/// pr_info!("The policy details are: {:?}\n", (policy.cpu(), policy.cur()));
/// }