[PATCH 5/5] ACPI: PM: Adjust behavior for field problems on AMD systems

[Mario Limonciello <mario.limonciello@amd.com>]

Some AMD Systems with uPEP _HID AMD004/AMDI005 have an off by one bug
in their function mask return.  This means that they will call entrance
but not exit for matching functions.

Other AMD systems with this HID should use the Microsoft generic UUID.

AMD systems with uPEP HID AMDI006 should be using the Microsoft method.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/acpi/x86/s2idle.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
index 3f2a90648ec9..816bf2c34b7a 100644
--- a/drivers/acpi/x86/s2idle.c
+++ b/drivers/acpi/x86/s2idle.c
@@ -371,12 +371,27 @@ static int lps0_device_attach(struct acpi_device *adev,
 		return 0;
 
 	if (acpi_s2idle_vendor_amd()) {
+		/* AMD0004, AMDI0005:
+		 * - Should use rev_id 0x0
+		 * - function mask > 0x3: Should use AMD method, but has off by one bug
+		 * - function mask = 0x3: Should use Microsoft method
+		 * AMDI0006:
+		 * - should use rev_id 0x0
+		 * - function mask = 0x3: Should use Microsoft method
+		 */
+		const char *hid = acpi_device_hid(adev);
 		rev_id = 0;
 		lps0_dsm_func_mask = validate_dsm(adev->handle,
 					ACPI_LPS0_DSM_UUID_AMD, rev_id, &lps0_dsm_guid);
 		lps0_dsm_func_mask_microsoft = validate_dsm(adev->handle,
 					ACPI_LPS0_DSM_UUID_MICROSOFT, rev_id,
 					&lps0_dsm_guid_microsoft);
+		if (lps0_dsm_func_mask > 0x3 && (!strcmp(hid, "AMD0004") ||
+						 !strcmp(hid, "AMDI0005"))) {
+			lps0_dsm_func_mask = (lps0_dsm_func_mask << 1) | 0x1;
+			acpi_handle_debug(adev->handle, "_DSM UUID %s: Adjusted function mask: 0x%x\n",
+					  ACPI_LPS0_DSM_UUID_AMD, lps0_dsm_func_mask);
+		}
 	} else {
 		rev_id = 1;
 		lps0_dsm_func_mask = validate_dsm(adev->handle,
-- 
2.25.1