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 though 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>
---
v1->v2:
* Change to an allow list for wmi-bmof and suffix the extra instances
drivers/platform/x86/wmi.c | 45 ++++++++++++++++++++++++++++++--------
1 file changed, 36 insertions(+), 9 deletions(-)
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index aed293b5af81..2997dad79e8b 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -105,6 +105,12 @@ 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",
@@ -1073,6 +1079,19 @@ static const struct device_type wmi_type_data = {
.release = wmi_dev_release,
};
+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)
@@ -1080,6 +1099,7 @@ static int wmi_create_device(struct device *wmi_bus_dev,
struct acpi_device_info *info;
char method[WMI_ACPI_METHOD_NAME_SIZE];
int result;
+ uint count;
if (wblock->gblock.flags & ACPI_WMI_EVENT) {
wblock->dev.dev.type = &wmi_type_event;
@@ -1134,7 +1154,11 @@ 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);
@@ -1154,11 +1178,20 @@ 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
@@ -1208,13 +1241,7 @@ 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(*wblock), GFP_KERNEL);
--
2.34.1
