6.6-stable review patch. If anyone has any objections, please let me know.
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From: Gautham R. Shenoy gautham.shenoy@amd.com
[ Upstream commit 6dd3b8a709a130a4d55c866af9804c81b8486d28 ]
per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online CPUs via acpi_soft_cpu_online() --> __acpi_processor_start() --> acpi_cppc_processor_probe().
However the function acpi_cpc_valid() checks for the validity of the _CPC object for all the present CPUs. This breaks when the kernel is booted with "nosmt=force".
Hence check the validity of the _CPC objects of only the online CPUs.
Fixes: 2aeca6bd0277 ("ACPI: CPPC: Check present CPUs for determining _CPC is valid") Reported-by: Christopher Harris chris.harris79@gmail.com Closes: https://lore.kernel.org/lkml/CAM+eXpdDT7KjLV0AxEwOLkSJ2QtrsvGvjA2cCHvt1d0k2_... Suggested-by: Mario Limonciello mario.limonciello@amd.com Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" superm1@kernel.org Tested-by: Chrisopher Harris chris.harris79@gmail.com Signed-off-by: Gautham R. Shenoy gautham.shenoy@amd.com Link: https://patch.msgid.link/20251107074145.2340-3-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 10d531427ba77..39f248be9611f 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -445,7 +445,7 @@ bool acpi_cpc_valid(void) if (acpi_disabled) return false;
- for_each_present_cpu(cpu) { + for_each_online_cpu(cpu) { cpc_ptr = per_cpu(cpc_desc_ptr, cpu); if (!cpc_ptr) return false;