ACPI: CPPC: Don't require flexible address space if X86_FEATURE_CPPC …

…is supported

[ Upstream commit 0907339 ]

Commit 0651ab9 ("ACPI: CPPC: Check _OSC for flexible address space")
changed _CPC probing to require flexible address space to be negotiated
for CPPC to work.

However it was observed that this caused a regression for Arek's ROG
Zephyrus G15 GA503QM which previously CPPC worked, but now it stopped
working.

To avoid causing a regression waive this failure when the CPU is known
to support CPPC.

Cc: Pierre Gondois <pierre.gondois@arm.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216248
Fixes: 0651ab9 ("ACPI: CPPC: Check _OSC for flexible address space")
Reported-and-tested-by: Arek Ruśniak <arek.rusi@gmail.com>
Signed-off-by: Mario Limonciello <mario.limonciello@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

@@ -764,7 +764,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 
 					if (!osc_cpc_flexible_adr_space_confirmed) {
 						pr_debug("Flexible address space capability not supported\n");
-						goto out_free;
+						if (!cpc_supported_by_cpu())
+							goto out_free;
 					}
 
 					addr = ioremap(gas_t->address, gas_t->bit_width/8);
@@ -791,7 +792,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 				}
 				if (!osc_cpc_flexible_adr_space_confirmed) {
 					pr_debug("Flexible address space capability not supported\n");
-					goto out_free;
+					if (!cpc_supported_by_cpu())
+						goto out_free;
 				}
 			} else {
 				if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) {