linux-kernel - [PATCH 2/2] platform/x86: wmi: Update documentation of WCxx/WExx ACPI methods

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Message-Id: <20250619221440.6737-2-W_Armin@gmx.de>
Date: Fri, 20 Jun 2025 00:14:40 +0200
From: Armin Wolf <W_Armin@....de>
To: dimich.dmb@...il.com,
	hdegoede@...hat.com,
	ilpo.jarvinen@...ux.intel.com,
	kuurtb@...il.com
Cc: corbet@....net,
	platform-driver-x86@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] platform/x86: wmi: Update documentation of WCxx/WExx ACPI methods

Inform potential firmware developers that WExx ACPI methods are
always called by the WMI driver core even if the associated WMI event
is not marked as being expensive.

Signed-off-by: Armin Wolf <W_Armin@....de>
---
 Documentation/wmi/acpi-interface.rst | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/Documentation/wmi/acpi-interface.rst b/Documentation/wmi/acpi-interface.rst
index f1b28835d23c..1ef003b033bf 100644
--- a/Documentation/wmi/acpi-interface.rst
+++ b/Documentation/wmi/acpi-interface.rst
@@ -36,7 +36,7 @@ Offset  Size (in bytes) Content
 
 The WMI object flags control whether the method or notification ID is used:
 
-- 0x1: Data block usage is expensive and must be explicitly enabled/disabled.
+- 0x1: Data block is expensive to collect.
 - 0x2: Data block contains WMI methods.
 - 0x4: Data block contains ASCIZ string.
 - 0x8: Data block describes a WMI event, use notification ID instead
@@ -83,14 +83,18 @@ event as hexadecimal value. Their first parameter is an integer with a value
 of 0 if the WMI event should be disabled, other values will enable
 the WMI event.
 
+Those ACPI methods are always called even for WMI events not registered as
+being expensive to collect to match the behavior of the Windows driver.
+
 WCxx ACPI methods
 -----------------
-Similar to the ``WExx`` ACPI methods, except that it controls data collection
-instead of events and thus the last two characters of the ACPI method name are
-the method ID of the data block to enable/disable.
+Similar to the ``WExx`` ACPI methods, except that instead of WMI events it controls
+data collection of data blocks registered as being expensive to collect. Thus the
+last two characters of the ACPI method name are the method ID of the data block
+to enable/disable.
 
 Those ACPI methods are also called before setting data blocks to match the
-behaviour of the Windows driver.
+behavior of the Windows driver.
 
 _WED ACPI method
 ----------------
-- 
2.39.5