5.15-stable review patch. If anyone has any objections, please let me know.
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From: Mario Limonciello mario.limonciello@amd.com
[ 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@amd.com Link: https://lore.kernel.org/r/20220829201500.6341-1-mario.limonciello@amd.com Reviewed-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com Stable-dep-of: cbf54f37600e ("platform/x86: wmi: Skip blocks with zero instances") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/wmi.c | 49 +++++++++++++++++++++++++++++++------- 1 file changed, 40 insertions(+), 9 deletions(-)
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);