linux-kernel - [PATCH v2 3/6] acpi/x86: s2idle: Add module parameter to prefer Microsoft GUID

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Message-ID: <20220912172401.22301-4-mario.limonciello@amd.com>
Date:   Mon, 12 Sep 2022 12:23:57 -0500
From:   Mario Limonciello <mario.limonciello@....com>
To:     <rafael@...nel.org>, <linux-kernel@...r.kernel.org>
CC:     <catalin@...ebit.com>, <philipp.zabel@...il.com>,
        <travisghansen@...oo.com>, <Shyam-sundar.S-k@....com>,
        Mario Limonciello <mario.limonciello@....com>,
        Len Brown <lenb@...nel.org>, <linux-acpi@...r.kernel.org>
Subject: [PATCH v2 3/6] acpi/x86: s2idle: Add module parameter to prefer Microsoft GUID

OEMs have made some mistakes in the past for the AMD GUID support
and not populated the method properly.  To add an escape hatch for
this problem introduce a module parameter that can force using
the Microsoft GUID.

This is intentionally introduced to both Intel and AMD codepaths
to allow using the parameter as a debugging tactic on either.

Signed-off-by: Mario Limonciello <mario.limonciello@....com>
---
 drivers/acpi/x86/s2idle.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
index a8256e5a0e8a..a9b0f2b54a1c 100644
--- a/drivers/acpi/x86/s2idle.c
+++ b/drivers/acpi/x86/s2idle.c
@@ -27,6 +27,10 @@ static bool sleep_no_lps0 __read_mostly;
 module_param(sleep_no_lps0, bool, 0644);
 MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface");
 
+static bool prefer_microsoft_guid __read_mostly;
+module_param(prefer_microsoft_guid, bool, 0644);
+MODULE_PARM_DESC(prefer_microsoft_guid, "Prefer selecting Microsoft GUID for LPS0 device");
+
 static const struct acpi_device_id lps0_device_ids[] = {
 	{"PNP0D80", },
 	{"", },
@@ -402,6 +406,9 @@ static int lps0_device_attach(struct acpi_device *adev,
 	if (lps0_device_handle)
 		return 0;
 
+	lps0_dsm_func_mask_microsoft = validate_dsm(adev->handle,
+						    ACPI_LPS0_DSM_UUID_MICROSOFT, 0,
+						    &lps0_dsm_guid_microsoft);
 	if (acpi_s2idle_vendor_amd()) {
 		static const struct acpi_device_id *dev_id;
 		const struct amd_lps0_hid_device_data *data;
@@ -416,16 +423,12 @@ static int lps0_device_attach(struct acpi_device *adev,
 		rev_id = data->rev_id;
 		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, 0,
-					&lps0_dsm_guid_microsoft);
 		if (lps0_dsm_func_mask > 0x3 && data->check_off_by_one) {
 			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 if (lps0_dsm_func_mask_microsoft > 0 && data->prefer_amd_guid &&
-				(!strcmp(hid, "AMDI0007") ||
-				 !strcmp(hid, "AMDI0008"))) {
+				!prefer_microsoft_guid) {
 			lps0_dsm_func_mask_microsoft = -EINVAL;
 			acpi_handle_debug(adev->handle, "_DSM Using AMD method\n");
 		}
@@ -433,7 +436,8 @@ static int lps0_device_attach(struct acpi_device *adev,
 		rev_id = 1;
 		lps0_dsm_func_mask = validate_dsm(adev->handle,
 					ACPI_LPS0_DSM_UUID, rev_id, &lps0_dsm_guid);
-		lps0_dsm_func_mask_microsoft = -EINVAL;
+		if (!prefer_microsoft_guid)
+			lps0_dsm_func_mask_microsoft = -EINVAL;
 	}
 
 	if (lps0_dsm_func_mask < 0 && lps0_dsm_func_mask_microsoft < 0)
-- 
2.34.1