From: Rafael J. Wysocki <[email protected]>
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 <[email protected]>
---
drivers/acpi/bus.c | 8 ++++++++
drivers/acpi/cppc_acpi.c | 3 +++
include/linux/acpi.h | 1 +
3 files changed, 12 insertions(+)
Index: linux-pm/drivers/acpi/bus.c
===================================================================
--- linux-pm.orig/drivers/acpi/bus.c
+++ linux-pm/drivers/acpi/bus.c
@@ -284,6 +284,8 @@ EXPORT_SYMBOL_GPL(osc_pc_lpi_support_con
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)
{
@@ -339,6 +341,12 @@ static void acpi_bus_osc_negotiate_platf
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.
Index: linux-pm/drivers/acpi/cppc_acpi.c
===================================================================
--- linux-pm.orig/drivers/acpi/cppc_acpi.c
+++ linux-pm/drivers/acpi/cppc_acpi.c
@@ -656,6 +656,9 @@ int acpi_cppc_processor_probe(struct acp
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);
Index: linux-pm/include/linux/acpi.h
===================================================================
--- linux-pm.orig/include/linux/acpi.h
+++ linux-pm/include/linux/acpi.h
@@ -580,6 +580,7 @@ acpi_status acpi_run_osc(acpi_handle han
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