From ebc4ed14a4dbf51307102bb7ffc82ed6c16a37c2 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 9 Sep 2025 09:38:19 +0200 Subject: [PATCH 01/10] cpufreq: mediatek: fix device leak on probe failure Make sure to drop the reference to the cci device taken by of_find_device_by_node() on probe failure (e.g. probe deferral). Fixes: 0daa47325bae ("cpufreq: mediatek: Link CCI device to CPU") Cc: Jia-Wei Chang Cc: Rex-BC Chen Signed-off-by: Johan Hovold Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: Chen-Yu Tsai Signed-off-by: Viresh Kumar --- drivers/cpufreq/mediatek-cpufreq.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) 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) From 24287f902095d845c6af9c2c369ba96877f5eb79 Mon Sep 17 00:00:00 2001 From: Thorsten Blum Date: Mon, 15 Sep 2025 15:59:54 +0200 Subject: [PATCH 02/10] rust: cpufreq: streamline find_supply_names Remove local variables from find_supply_names() and use .and_then() with the more concise kernel::kvec![] macro, instead of KVec::with_capacity() followed by .push() and Some(). No functional changes intended. Signed-off-by: Thorsten Blum Signed-off-by: Viresh Kumar --- drivers/cpufreq/rcpufreq_dt.rs | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/cpufreq/rcpufreq_dt.rs b/drivers/cpufreq/rcpufreq_dt.rs index 7e1fbf9a091f..224d063c7cec 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 { /// Finds supply name for the CPU from DT. fn find_supply_names(dev: &Device, cpu: cpu::CpuId) -> Option> { // 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. From 0b1bb980fd7cae126ee3d59f817068a13e321b07 Mon Sep 17 00:00:00 2001 From: Aaron Kling Date: Thu, 28 Aug 2025 21:48:12 -0500 Subject: [PATCH 03/10] cpufreq: tegra186: Set target frequency for all cpus in policy The original commit set all cores in a cluster to a shared policy, but did not update set_target to apply a frequency change to all cores for the policy. This caused most cores to remain stuck at their boot frequency. Fixes: be4ae8c19492 ("cpufreq: tegra186: Share policy per cluster") Signed-off-by: Aaron Kling Reviewed-by: Mikko Perttunen Signed-off-by: Viresh Kumar --- drivers/cpufreq/tegra186-cpufreq.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/tegra186-cpufreq.c b/drivers/cpufreq/tegra186-cpufreq.c index 4270686fc3e3..a9e1f9bd2a4e 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; } From ba6018929165fc914c665f071f8e8cdbac844a49 Mon Sep 17 00:00:00 2001 From: Aaron Kling Date: Thu, 28 Aug 2025 21:48:13 -0500 Subject: [PATCH 04/10] cpufreq: tegra186: Initialize all cores to max frequencies During initialization, the EDVD_COREx_VOLT_FREQ registers for some cores are still at reset values and not reflecting the actual frequency. This causes get calls to fail. Set all cores to their respective max frequency during probe to initialize the registers to working values. Suggested-by: Mikko Perttunen Signed-off-by: Aaron Kling Reviewed-by: Mikko Perttunen Signed-off-by: Viresh Kumar --- drivers/cpufreq/tegra186-cpufreq.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/cpufreq/tegra186-cpufreq.c b/drivers/cpufreq/tegra186-cpufreq.c index a9e1f9bd2a4e..136ab102f636 100644 --- a/drivers/cpufreq/tegra186-cpufreq.c +++ b/drivers/cpufreq/tegra186-cpufreq.c @@ -136,13 +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; @@ -172,6 +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]; @@ -182,10 +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); @@ -227,7 +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), @@ -250,10 +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); + } } } From f97aef092e199c10a3da96ae79b571edd5362faa Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 26 Sep 2025 12:12:37 +0200 Subject: [PATCH 05/10] cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency Commit a755d0e2d41b ("cpufreq: Honour transition_latency over transition_delay_us") caused platforms where cpuinfo.transition_latency is CPUFREQ_ETERNAL to get a very large transition latency whereas previously it had been capped at 10 ms (and later at 2 ms). This led to a user-observable regression between 6.6 and 6.12 as described by Shawn: "The dbs sampling_rate was 10000 us on 6.6 and suddently becomes 6442450 us (4294967295 / 1000 * 1.5) on 6.12 for these platforms because the default transition delay was dropped [...]. It slows down dbs governor's reacting to CPU loading change dramatically. Also, as transition_delay_us is used by schedutil governor as rate_limit_us, it shows a negative impact on device idle power consumption, because the device gets slightly less time in the lowest OPP." Evidently, the expectation of the drivers using CPUFREQ_ETERNAL as cpuinfo.transition_latency was that it would be capped by the core, but they may as well return a default transition latency value instead of CPUFREQ_ETERNAL and the core need not do anything with it. Accordingly, introduce CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS and make all of the drivers in question use it instead of CPUFREQ_ETERNAL. Also update the related Rust binding. Fixes: a755d0e2d41b ("cpufreq: Honour transition_latency over transition_delay_us") Closes: https://lore.kernel.org/linux-pm/20250922125929.453444-1-shawnguo2@yeah.net/ Reported-by: Shawn Guo Reviewed-by: Mario Limonciello (AMD) Reviewed-by: Jie Zhan Acked-by: Viresh Kumar Cc: 6.6+ # 6.6+ Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/2264949.irdbgypaU6@rafael.j.wysocki [ rjw: Fix typo in new symbol name, drop redundant type cast from Rust binding ] Tested-by: Shawn Guo # with cpufreq-dt driver Reviewed-by: Qais Yousef Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq-dt.c | 2 +- drivers/cpufreq/imx6q-cpufreq.c | 2 +- drivers/cpufreq/mediatek-cpufreq-hw.c | 2 +- drivers/cpufreq/rcpufreq_dt.rs | 2 +- drivers/cpufreq/scmi-cpufreq.c | 2 +- drivers/cpufreq/scpi-cpufreq.c | 2 +- drivers/cpufreq/spear-cpufreq.c | 2 +- include/linux/cpufreq.h | 3 +++ rust/kernel/cpufreq.rs | 7 ++++--- 9 files changed, 14 insertions(+), 10 deletions(-) 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/rcpufreq_dt.rs b/drivers/cpufreq/rcpufreq_dt.rs index 7e1fbf9a091f..3909022e1c74 100644 --- a/drivers/cpufreq/rcpufreq_dt.rs +++ b/drivers/cpufreq/rcpufreq_dt.rs @@ -123,7 +123,7 @@ 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/include/linux/cpufreq.h b/include/linux/cpufreq.h index 40966512ea18..bc8c083bc16a 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -32,6 +32,9 @@ */ #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 eea57ba95f24..2ea735700ae7 100644 --- a/rust/kernel/cpufreq.rs +++ b/rust/kernel/cpufreq.rs @@ -39,7 +39,8 @@ 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 { @@ -400,13 +401,13 @@ 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())); /// } From f965d111e68f4a993cc44d487d416e3d954eea11 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 26 Sep 2025 12:19:41 +0200 Subject: [PATCH 06/10] cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay If cppc_get_transition_latency() returns CPUFREQ_ETERNAL to indicate a failure to retrieve the transition latency value from the platform firmware, the CPPC cpufreq driver will use that value (converted to microseconds) as the policy transition delay, but it is way too large for any practical use. Address this by making the driver use the cpufreq's default transition latency value (in microseconds) as the transition delay if CPUFREQ_ETERNAL is returned by cppc_get_transition_latency(). Fixes: d4f3388afd48 ("cpufreq / CPPC: Set platform specific transition_delay_us") Cc: 5.19+ # 5.19 Signed-off-by: Rafael J. Wysocki Reviewed-by: Mario Limonciello (AMD) Reviewed-by: Jie Zhan Acked-by: Viresh Kumar Reviewed-by: Qais Yousef --- drivers/cpufreq/cppc_cpufreq.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 12de0ac7bbaf..b71946937c52 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) +{ + unsigned int transition_latency_ns = cppc_get_transition_latency(cpu); + + if (transition_latency_ns == CPUFREQ_ETERNAL) + 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 From c28a280bd465690981099cd6e43dfcfa5c28b133 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 26 Sep 2025 12:29:50 +0200 Subject: [PATCH 07/10] ACPI: CPPC: Do not use CPUFREQ_ETERNAL as an error value Instead of using CPUFREQ_ETERNAL for signaling an error condition in cppc_get_transition_latency(), change the return value type of that function to int and make it return a proper negative error code on failures. No intentional functional impact. Reviewed-by: Mario Limonciello (AMD) Reviewed-by: Jie Zhan Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Reviewed-by: Qais Yousef --- drivers/acpi/cppc_acpi.c | 16 +++++++--------- drivers/cpufreq/amd-pstate.c | 8 ++++---- drivers/cpufreq/cppc_cpufreq.c | 4 ++-- include/acpi/cppc_acpi.h | 6 +++--- 4 files changed, 16 insertions(+), 18 deletions(-) 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 b71946937c52..e23d9abea135 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -310,9 +310,9 @@ static int cppc_verify_policy(struct cpufreq_policy_data *policy) static unsigned int __cppc_cpufreq_get_transition_delay_us(unsigned int cpu) { - unsigned int transition_latency_ns = cppc_get_transition_latency(cpu); + int transition_latency_ns = cppc_get_transition_latency(cpu); - if (transition_latency_ns == CPUFREQ_ETERNAL) + if (transition_latency_ns < 0) return CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS / NSEC_PER_USEC; return transition_latency_ns / NSEC_PER_USEC; 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) { From 950c6451a5c38d375993c3b9da427e2e69b01c30 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 26 Sep 2025 12:31:47 +0200 Subject: [PATCH 08/10] cpufreq: Drop unused symbol CPUFREQ_ETERNAL Drop CPUFREQ_ETERNAL that has no users any more along with all references to it in the documentation. No functional impact. Reviewed-by: Mario Limonciello (AMD) Reviewed-by: Jie Zhan Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Reviewed-by: Qais Yousef --- Documentation/admin-guide/pm/cpufreq.rst | 4 ---- Documentation/cpu-freq/cpu-drivers.rst | 3 +-- Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst | 3 +-- Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst | 3 +-- include/linux/cpufreq.h | 5 ----- 5 files changed, 3 insertions(+), 15 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..8238f4c6e4f5 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..5435c3928d4b 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/include/linux/cpufreq.h b/include/linux/cpufreq.h index bc8c083bc16a..0465d1e6f72a 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -26,13 +26,8 @@ *********************************************************************/ /* * 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 From 989ed3cad2fdb7921bf0f9f0f730e1bb065946c2 Mon Sep 17 00:00:00 2001 From: Gopi Krishna Menon Date: Fri, 3 Oct 2025 23:06:00 +0530 Subject: [PATCH 09/10] docs/zh_TW: Fix malformed table Running "make htmldocs" generate the following build error in zh_TW/cpu-freq/cpu-drivers.rst: Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst:109: ERROR: Malformed table. Fix the table formatting to resolve the error. Signed-off-by: Gopi Krishna Menon Signed-off-by: Rafael J. Wysocki --- Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst b/Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst index 5435c3928d4b..7f751a7add56 100644 --- a/Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst +++ b/Documentation/translations/zh_TW/cpu-freq/cpu-drivers.rst @@ -112,7 +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 | +| | 納秒爲單位 | | | | +-----------------------------------+--------------------------------------+ |policy->cur | 該CPU當前的工作頻率(如適用) | From 7e8f305a081e22ce81aab7f7b9ce01437cbd38b3 Mon Sep 17 00:00:00 2001 From: Gopi Krishna Menon Date: Fri, 3 Oct 2025 23:05:59 +0530 Subject: [PATCH 10/10] docs/zh_CN: Fix malformed table Running "make htmldocs" generates the following build error in zh_CN/cpu-freq/cpu-drivers.rst: Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst:109: ERROR: Malformed table. Fix the table formatting to resolve the error. Signed-off-by: Gopi Krishna Menon Signed-off-by: Rafael J. Wysocki --- Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst b/Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst index 8238f4c6e4f5..2d5e84d8e58d 100644 --- a/Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst +++ b/Documentation/translations/zh_CN/cpu-freq/cpu-drivers.rst @@ -112,7 +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 | +| | 纳秒为单位 | | | | +-----------------------------------+--------------------------------------+ |policy->cur | 该CPU当前的工作频率(如适用) |