Re: [PATCH v2 03/21] ACPI: CPPC: Check online CPUs for determining _CPC is valid
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: 2021-10-19 16:52:52
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On Sun, Sep 26, 2021 at 11:06 AM Huang Rui [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Mario Limonciello <mario.limonciello@amd.com> As this is a static check, it should be based upon what is currently present on the system. This makes probeing more deterministic. While local APIC flags field (lapic_flags) of cpu core in MADT table is 0, then the cpu core won't be enabled. In this case, _CPC won't be found in this core, and return back to _CPC invalid with walking through possible cpus (include disable cpus). This is not expected, so switch to check online CPUs instead. Reported-by: Jinzhou Su <redacted> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Huang Rui <ray.huang@amd.com> --- drivers/acpi/cppc_acpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index a4d4eebba1da..2efe2ba97d96 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c@@ -411,7 +411,7 @@ bool acpi_cpc_valid(void) struct cpc_desc *cpc_ptr; int cpu; - for_each_possible_cpu(cpu) { + for_each_online_cpu(cpu) {
Shouldn't this be for_each_present_cpu()? In case a CPU is present, but not online when cppc_cpufreq is loaded?
cpc_ptr = per_cpu(cpc_desc_ptr, cpu);
if (!cpc_ptr)
return false;
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