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Commitcac173bea5("ACPI: processor: idle: Rework the handling of acpi_processor_ffh_lpi_probe()") moved the acpi_processor_ffh_lpi_probe() call from acpi_processor_setup_cpuidle_dev(), where its return value was ignored, to acpi_processor_get_power_info(), where it is now treated as a hard failure. As a result, platforms where psci_acpi_cpu_init_idle() returned -ENODEV stopped registering any cpuidle states, forcing CPUs to busy-poll when idle. On NVIDIA Grace (aarch64) systems with PSCIv1.1, pr->power.count is 1 (only WFI, no deep PSCI states beyond it), so the previous "count = pr->power.count - 1; if (count <= 0) return -ENODEV;" check returned -ENODEV for all 72 CPUs and disabled cpuidle entirely. The lpi_states count is already validated in acpi_processor_get_lpi_info(), so the check here is redundant. Simplify the loop to iterate over lpi_states[1..power.count). When only WFI is present, the loop body simply does not execute and the function returns 0, which is the correct outcome: there is nothing to validate for FFH and no error to report. Suggested-by: Huisong Li <lihuisong@huawei.com> Cc: stable@vger.kernel.org Fixes:cac173bea5("ACPI: processor: idle: Rework the handling of acpi_processor_ffh_lpi_probe()") Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Sudeep Holla <sudeep.holla@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
67 lines
1.5 KiB
C
67 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* ARM64 CPU idle arch support
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*
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* Copyright (C) 2014 ARM Ltd.
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* Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
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*/
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#include <linux/acpi.h>
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#include <linux/cpuidle.h>
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#include <linux/cpu_pm.h>
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#include <linux/psci.h>
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#include <acpi/processor.h>
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#define ARM64_LPI_IS_RETENTION_STATE(arch_flags) (!(arch_flags))
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static int psci_acpi_cpu_init_idle(unsigned int cpu)
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{
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int i;
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struct acpi_lpi_state *lpi;
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struct acpi_processor *pr = per_cpu(processors, cpu);
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if (unlikely(!pr || !pr->flags.has_lpi))
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return -EINVAL;
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/*
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* If the PSCI cpu_suspend function hook has not been initialized
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* idle states must not be enabled, so bail out
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*/
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if (!psci_ops.cpu_suspend)
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return -EOPNOTSUPP;
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for (i = 1; i < pr->power.count; i++) {
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u32 state;
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lpi = &pr->power.lpi_states[i];
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/*
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* Only bits[31:0] represent a PSCI power_state while
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* bits[63:32] must be 0x0 as per ARM ACPI FFH Specification
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*/
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state = lpi->address;
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if (!psci_power_state_is_valid(state)) {
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pr_warn("Invalid PSCI power state %#x\n", state);
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return -EINVAL;
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}
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}
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return 0;
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}
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int acpi_processor_ffh_lpi_probe(unsigned int cpu)
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{
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return psci_acpi_cpu_init_idle(cpu);
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}
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__cpuidle int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
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{
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u32 state = lpi->address;
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if (ARM64_LPI_IS_RETENTION_STATE(lpi->arch_flags))
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return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM_RCU(psci_cpu_suspend_enter,
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lpi->index, state);
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else
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return CPU_PM_CPU_IDLE_ENTER_PARAM_RCU(psci_cpu_suspend_enter,
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lpi->index, state);
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}
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