This is a note to let you know that I've just added the patch titled
platform/x86: wmi: Allow duplicate GUIDs for drivers that use struct wmi_driver
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
platform-x86-wmi-allow-duplicate-guids-for-drivers-t.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0b6fb9b0fe953cb2c95b405f916e366004223d8d
Author: Mario Limonciello <mario.limonciello@xxxxxxx>
Date: Mon Aug 29 15:14:59 2022 -0500
platform/x86: wmi: Allow duplicate GUIDs for drivers that use struct wmi_driver
[ Upstream commit 134038b075cb1dae21623499d765973d286ac94a ]
The WMI subsystem in the kernel currently tracks WMI devices by
a GUID string not by ACPI device. The GUID used by the `wmi-bmof`
module however is available from many devices on nearly every machine.
This originally was thought to be a bug, but as it happens on most
machines it is a design mistake. It has been fixed by tying an ACPI
device to the driver with struct wmi_driver. So drivers that have
moved over to struct wmi_driver can actually support multiple
instantiations of a GUID without any problem.
Add an allow list into wmi.c for GUIDs that the drivers that are known
to use struct wmi_driver. The list is populated with `wmi-bmof` right
now. The additional instances of that in sysfs with be suffixed with -%d
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Link: https://lore.kernel.org/r/20220829201500.6341-1-mario.limonciello@xxxxxxx
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Stable-dep-of: cbf54f37600e ("platform/x86: wmi: Skip blocks with zero instances")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 63265ab964245..ce3380f09a472 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -99,6 +99,12 @@ static const struct acpi_device_id wmi_device_ids[] = {
};
MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
+/* allow duplicate GUIDs as these device drivers use struct wmi_driver */
+static const char * const allow_duplicates[] = {
+ "05901221-D566-11D1-B2F0-00A0C9062910", /* wmi-bmof */
+ NULL
+};
+
static struct platform_driver acpi_wmi_driver = {
.driver = {
.name = "acpi-wmi",
@@ -1039,6 +1045,23 @@ static const struct device_type wmi_type_data = {
.release = wmi_dev_release,
};
+/*
+ * _WDG is a static list that is only parsed at startup,
+ * so it's safe to count entries without extra protection.
+ */
+static int guid_count(const guid_t *guid)
+{
+ struct wmi_block *wblock;
+ int count = 0;
+
+ list_for_each_entry(wblock, &wmi_block_list, list) {
+ if (guid_equal(&wblock->gblock.guid, guid))
+ count++;
+ }
+
+ return count;
+}
+
static int wmi_create_device(struct device *wmi_bus_dev,
struct wmi_block *wblock,
struct acpi_device *device)
@@ -1046,6 +1069,7 @@ static int wmi_create_device(struct device *wmi_bus_dev,
struct acpi_device_info *info;
char method[5];
int result;
+ uint count;
if (wblock->gblock.flags & ACPI_WMI_EVENT) {
wblock->dev.dev.type = &wmi_type_event;
@@ -1102,7 +1126,11 @@ static int wmi_create_device(struct device *wmi_bus_dev,
wblock->dev.dev.bus = &wmi_bus_type;
wblock->dev.dev.parent = wmi_bus_dev;
- dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
+ count = guid_count(&wblock->gblock.guid);
+ if (count)
+ dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
+ else
+ dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
device_initialize(&wblock->dev.dev);
@@ -1122,11 +1150,20 @@ static void wmi_free_devices(struct acpi_device *device)
}
}
-static bool guid_already_parsed(struct acpi_device *device, const guid_t *guid)
+static bool guid_already_parsed_for_legacy(struct acpi_device *device, const guid_t *guid)
{
struct wmi_block *wblock;
list_for_each_entry(wblock, &wmi_block_list, list) {
+ /* skip warning and register if we know the driver will use struct wmi_driver */
+ for (int i = 0; allow_duplicates[i] != NULL; i++) {
+ guid_t tmp;
+
+ if (guid_parse(allow_duplicates[i], &tmp))
+ continue;
+ if (guid_equal(&tmp, guid))
+ return false;
+ }
if (guid_equal(&wblock->gblock.guid, guid)) {
/*
* Because we historically didn't track the relationship
@@ -1176,13 +1213,7 @@ static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
if (debug_dump_wdg)
wmi_dump_wdg(&gblock[i]);
- /*
- * Some WMI devices, like those for nVidia hooks, have a
- * duplicate GUID. It's not clear what we should do in this
- * case yet, so for now, we'll just ignore the duplicate
- * for device creation.
- */
- if (guid_already_parsed(device, &gblock[i].guid))
+ if (guid_already_parsed_for_legacy(device, &gblock[i].guid))
continue;
wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
