[lkml]   [2021]   [Nov]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH v5 04/22] ACPI: CPPC: Check present CPUs for determining _CPC is valid
From: Mario Limonciello <>

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 present CPUs instead.

Reported-by: Jinzhou Su <>
Signed-off-by: Mario Limonciello <>
Signed-off-by: Huang Rui <>
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 ca62c3dc9899..a46f227dc254 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_present_cpu(cpu) {
cpc_ptr = per_cpu(cpc_desc_ptr, cpu);
if (!cpc_ptr)
return false;
 \ /
  Last update: 2021-11-30 13:39    [W:0.319 / U:4.408 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site