linux-kernel - [PATCH v1 02/10] platform/x86: msi-wmi-platform: Add unlocked msi_wmi_platform

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Message-ID: <20250511204427.327558-3-lkml@antheas.dev>
Date: Sun, 11 May 2025 22:44:19 +0200
From: Antheas Kapenekakis <lkml@...heas.dev>
To: platform-driver-x86@...r.kernel.org
Cc: Armin Wolf <W_Armin@....de>,
	Jonathan Corbet <corbet@....net>,
	Hans de Goede <hdegoede@...hat.com>,
	Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	Jean Delvare <jdelvare@...e.com>,
	Guenter Roeck <linux@...ck-us.net>,
	Kurt Borja <kuurtb@...il.com>,
	linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-hwmon@...r.kernel.org,
	Antheas Kapenekakis <lkml@...heas.dev>
Subject: [PATCH v1 02/10] platform/x86: msi-wmi-platform: Add unlocked
 msi_wmi_platform_query

This driver requires to be able to handle transactions that perform
multiple WMI actions at a time. Therefore, it needs to be able to
lock the wmi_lock mutex for multiple operations.

Add msi_wmi_platform_query_unlocked() to allow the caller to
perform the WMI query without locking the wmi_lock mutex, by
renaming the existing function and adding a new one that only
locks the mutex.

Signed-off-by: Antheas Kapenekakis <lkml@...heas.dev>
---
 drivers/platform/x86/msi-wmi-platform.c | 27 ++++++++++++++++---------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/platform/x86/msi-wmi-platform.c b/drivers/platform/x86/msi-wmi-platform.c
index 41218a9d6e35d..f0d1b8e1a2fec 100644
--- a/drivers/platform/x86/msi-wmi-platform.c
+++ b/drivers/platform/x86/msi-wmi-platform.c
@@ -140,7 +140,7 @@ static int msi_wmi_platform_parse_buffer(union acpi_object *obj, u8 *output, siz
 	return 0;
 }
 
-static int msi_wmi_platform_query(struct msi_wmi_platform_data *data,
+static int msi_wmi_platform_query_unlocked(struct msi_wmi_platform_data *data,
 				  enum msi_wmi_platform_method method, u8 *buffer,
 				  size_t length)
 {
@@ -156,15 +156,9 @@ static int msi_wmi_platform_query(struct msi_wmi_platform_data *data,
 	if (!length)
 		return -EINVAL;
 
-	/*
-	 * The ACPI control method responsible for handling the WMI method calls
-	 * is not thread-safe. Because of this we have to do the locking ourself.
-	 */
-	scoped_guard(mutex, &data->wmi_lock) {
-		status = wmidev_evaluate_method(data->wdev, 0x0, method, &in, &out);
-		if (ACPI_FAILURE(status))
-			return -EIO;
-	}
+	status = wmidev_evaluate_method(data->wdev, 0x0, method, &in, &out);
+	if (ACPI_FAILURE(status))
+		return -EIO;
 
 	obj = out.pointer;
 	if (!obj)
@@ -176,6 +170,19 @@ static int msi_wmi_platform_query(struct msi_wmi_platform_data *data,
 	return ret;
 }
 
+static int msi_wmi_platform_query(struct msi_wmi_platform_data *data,
+				  enum msi_wmi_platform_method method, u8 *buffer,
+				  size_t length)
+{
+	/*
+	 * The ACPI control method responsible for handling the WMI method calls
+	 * is not thread-safe. Because of this we have to do the locking ourself.
+	 */
+	scoped_guard(mutex, &data->wmi_lock) {
+		return msi_wmi_platform_query_unlocked(data, method, buffer, length);
+	}
+}
+
 static umode_t msi_wmi_platform_is_visible(const void *drvdata, enum hwmon_sensor_types type,
 					   u32 attr, int channel)
 {
-- 
2.49.0