linux-kernel - [PATCH 6/7] platform/x86: wmi: Call WCxx methods when setting data blocks

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Message-Id: <20250203182322.384883-7-W_Armin@gmx.de>
Date: Mon,  3 Feb 2025 19:23:21 +0100
From: Armin Wolf <W_Armin@....de>
To: james@...iv.tech,
	markpearson@...ovo.com,
	jorge.lopez2@...com
Cc: jdelvare@...e.com,
	linux@...ck-us.net,
	linux-hwmon@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	hdegoede@...hat.com,
	ilpo.jarvinen@...ux.intel.com,
	platform-driver-x86@...r.kernel.org,
	corbet@....net,
	linux-doc@...r.kernel.org
Subject: [PATCH 6/7] platform/x86: wmi: Call WCxx methods when setting data blocks

After performing some tests with a custom SSDT table available at
https://github.com/Wer-Wolf/acpi-wmi-ssdt i found out that Windows
also enables data block collection even when the data block is
being set.

Emulate this behaviour to avoid confusing the ACPI firmware.
The bus-based API already implements this behaviour, so only the
legacy GUID-based API needs to be changed.

Signed-off-by: Armin Wolf <W_Armin@....de>
---
 Documentation/wmi/acpi-interface.rst | 3 +++
 drivers/platform/x86/wmi.c           | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/Documentation/wmi/acpi-interface.rst b/Documentation/wmi/acpi-interface.rst
index 06fb7fcf4413..f1b28835d23c 100644
--- a/Documentation/wmi/acpi-interface.rst
+++ b/Documentation/wmi/acpi-interface.rst
@@ -89,6 +89,9 @@ 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.

+Those ACPI methods are also called before setting data blocks to match the
+behaviour of the Windows driver.
+
 _WED ACPI method
 ----------------

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 01d4ac480930..2b2e405955cd 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -461,8 +461,14 @@ acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acp
 	if (IS_ERR(wdev))
 		return AE_ERROR;

+	if (wmi_device_enable(wdev, true) < 0)
+		dev_warn(&wdev->dev, "Failed to enable device\n");
+
 	status =  wmidev_block_set(wdev, instance, in);

+	if (wmi_device_enable(wdev, false) < 0)
+		dev_warn(&wdev->dev, "Failed to disable device\n");
+
 	wmi_device_put(wdev);

 	return status;
--
2.39.5