This is a note to let you know that I've just added the patch titled
ACPI: CPPC: Check present CPUs for determining _CPC is valid
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
acpi-cppc-check-present-cpus-for-determining-_cpc-is.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 34a5b49d40b9d235a55db22dc76e1b88f2338210
Author: Mario Limonciello <mario.limonciello@xxxxxxx>
Date: Fri Dec 24 09:04:58 2021 +0800
ACPI: CPPC: Check present CPUs for determining _CPC is valid
[ Upstream commit 2aeca6bd02776d7f56a49a32be0dd184f204d888 ]
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 <Jinzhou.Su@xxxxxxx>
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 3fbb17ecce2d5..6fe28a2d387bd 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;
