[PATCH 2/2] ACPI: let BIOS fall back to legacy handling if PRM disabled

From: Aubrey Li
Date: Fri Jul 02 2021 - 03:03:39 EST


Based on _OSC PRM bit, BIOS can choose switch from legacy handling
to using PRM. So if CONFIG_ACPI_PRMT is disabled, this bit should
not be set to let BIOS fall back to the legacy handling (such as SMI).

Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Aubrey Li <aubrey.li@xxxxxxxxxxxxxxx>
---
drivers/acpi/bus.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 60fb6a84..30a3d4a 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -303,7 +303,9 @@ static void acpi_bus_osc_negotiate_platform_control(void)

capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PCLPI_SUPPORT;
+#ifdef CONFIG_ACPI_PRMT
capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PRM_SUPPORT;
+#endif

#ifdef CONFIG_ARM64
capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_GENERIC_INITIATOR_SUPPORT;
--
2.7.4