[PATCH 1/3] platform/x86: wmi: Ignore duplicated GUIDs in legacy matches

[Armin Wolf <W_Armin@gmx.de>]

When matching a WMI device to a GUID used by the legacy GUID-based
API, devices with a duplicated GUID should be ignored.

Add an additional WMI device flag signaling that the GUID used by
the WMI device is also used by another WMI device. Ignore such
devices inside the match functions used by the legacy GUID-based API.

Tested on a ASUS Prime B650-Plus.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/platform/x86/wmi.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index abd0183c4107..29dfe52eb802 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -57,6 +57,7 @@ static_assert(__alignof__(struct guid_block) == 1);

 enum {	/* wmi_block flags */
 	WMI_READ_TAKES_NO_ARGS,
+	WMI_GUID_DUPLICATED,
 	WMI_NO_EVENT_DATA,
 };

@@ -196,6 +197,12 @@ static int wmidev_match_guid(struct device *dev, const void *data)
 	struct wmi_block *wblock = dev_to_wblock(dev);
 	const guid_t *guid = data;

+	/* Legacy GUID-based functions are restricted to only see
+	 * a single WMI device for each GUID.
+	 */
+	if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
+		return 0;
+
 	if (guid_equal(guid, &wblock->gblock.guid))
 		return 1;

@@ -207,6 +214,12 @@ static int wmidev_match_notify_id(struct device *dev, const void *data)
 	struct wmi_block *wblock = dev_to_wblock(dev);
 	const u32 *notify_id = data;

+	/* Legacy GUID-based functions are restricted to only see
+	 * a single WMI device for each GUID.
+	 */
+	if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
+		return 0;
+
 	if (wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *notify_id)
 		return 1;

@@ -1036,10 +1049,12 @@ static int wmi_create_device(struct device *wmi_bus_dev,
 	wblock->dev.dev.parent = wmi_bus_dev;

 	count = guid_count(&wblock->gblock.guid);
-	if (count)
+	if (count) {
 		dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
-	else
+		set_bit(WMI_GUID_DUPLICATED, &wblock->flags);
+	} else {
 		dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
+	}

 	device_initialize(&wblock->dev.dev);

--
2.39.2