ACPI: bus: Avoid using CPPC if not supported by firmware

If the platform firmware indicates that it does not support CPPC by
clearing the OSC_SB_CPC_SUPPORT and OSC_SB_CPCV2_SUPPORT bits in the
platform _OSC capabilities mask, avoid attempting to evaluate _CPC
which may fail in that case.

Because the OSC_SB_CPC_SUPPORT and OSC_SB_CPCV2_SUPPORT bits are only
added to the supported platform capabilities mask on x86, when
X86_FEATURE_HWP is supported, allow _CPC to be evaluated regardless
in the other cases.

Link: https://lore.kernel.org/linux-acpi/CAJZ5v0i=ecAksq0TV+iLVObm-=fUfdqPABzzkgm9K6KxO1ZCcg@mail.gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This commit is contained in:
Rafael J. Wysocki 2022-03-16 13:39:03 +01:00
parent 2ca8e62852
commit c42fa24b44
3 changed files with 12 additions and 0 deletions

View file

@ -283,6 +283,8 @@ EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed);
bool osc_sb_native_usb4_support_confirmed;
EXPORT_SYMBOL_GPL(osc_sb_native_usb4_support_confirmed);
bool osc_sb_cppc_not_supported;
static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
static void acpi_bus_osc_negotiate_platform_control(void)
{
@ -338,6 +340,12 @@ static void acpi_bus_osc_negotiate_platform_control(void)
return;
}
#ifdef CONFIG_X86
if (boot_cpu_has(X86_FEATURE_HWP))
osc_sb_cppc_not_supported = !(capbuf_ret[OSC_SUPPORT_DWORD] &
(OSC_SB_CPC_SUPPORT | OSC_SB_CPCV2_SUPPORT));
#endif
/*
* Now run _OSC again with query flag clear and with the caps
* supported by both the OS and the platform.

View file

@ -656,6 +656,9 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
acpi_status status;
int ret = -EFAULT;
if (osc_sb_cppc_not_supported)
return -ENODEV;
/* Parse the ACPI _CPC table for this CPU. */
status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output,
ACPI_TYPE_PACKAGE);

View file

@ -580,6 +580,7 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context);
extern bool osc_sb_apei_support_acked;
extern bool osc_pc_lpi_support_confirmed;
extern bool osc_sb_native_usb4_support_confirmed;
extern bool osc_sb_cppc_not_supported;
/* USB4 Capabilities */
#define OSC_USB_USB3_TUNNELING 0x00000001