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author | Mario Limonciello <mario.limonciello@amd.com> | 2022-08-29 15:14:59 -0500 |
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committer | Hans de Goede <hdegoede@redhat.com> | 2022-09-03 13:11:40 +0200 |
commit | 134038b075cb1dae21623499d765973d286ac94a (patch) | |
tree | 9c7f3e1e4fba744e22a2885fa1fe7916f6833c51 | |
parent | a2bdf10ce96efbccabdad7216db5587c1213996c (diff) | |
download | linux-stable-134038b075cb1dae21623499d765973d286ac94a.tar.gz linux-stable-134038b075cb1dae21623499d765973d286ac94a.tar.bz2 linux-stable-134038b075cb1dae21623499d765973d286ac94a.zip |
platform/x86: wmi: Allow duplicate GUIDs for drivers that use struct wmi_driver
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>
-rw-r--r-- | drivers/platform/x86/wmi.c | 49 |
1 files changed, 40 insertions, 9 deletions
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index aed293b5af81..aff23309b5d3 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 +1079,23 @@ 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) @@ -1080,6 +1103,7 @@ 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 +1158,11 @@ 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 +1182,20 @@ 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 +1245,7 @@ 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); |