ACPI: WMI: Survive BIOS with duplicate GUIDs

It would appear that in BIOS's with nVidia hooks, the GUID
05901221-D566-11D1-B2F0-00A0C9062910 is duplicated. For now, the simplest
solution is to just ignore any duplicate GUIDs. These particular hooks are not
currently supported/ used in the kernel, so whoever does that can figure out
what the 'right' solution should be (if there's a better one).

http://bugzilla.kernel.org/show_bug.cgi?id=14846

Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Reported-by: Oldřich Jedlička <oldium.pro@seznam.cz>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Carlos Corbacho 2009-12-26 19:14:59 +00:00 committed by Len Brown
parent 7a9568f536
commit d1f9e49707

View File

@ -714,6 +714,22 @@ static int wmi_class_init(void)
return ret;
}
static bool guid_already_parsed(const char *guid_string)
{
struct guid_block *gblock;
struct wmi_block *wblock;
struct list_head *p;
list_for_each(p, &wmi_blocks.list) {
wblock = list_entry(p, struct wmi_block, list);
gblock = &wblock->gblock;
if (strncmp(gblock->guid, guid_string, 16) == 0)
return true;
}
return false;
}
/*
* Parse the _WDG method for the GUID data blocks
*/
@ -723,6 +739,7 @@ static __init acpi_status parse_wdg(acpi_handle handle)
union acpi_object *obj;
struct guid_block *gblock;
struct wmi_block *wblock;
char guid_string[37];
acpi_status status;
u32 i, total;
@ -745,6 +762,19 @@ static __init acpi_status parse_wdg(acpi_handle handle)
memcpy(gblock, obj->buffer.pointer, obj->buffer.length);
for (i = 0; i < total; 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.
Anyone who wants to add support for that device can come
up with a better workaround for the mess then.
*/
if (guid_already_parsed(gblock[i].guid) == true) {
wmi_gtoa(gblock[i].guid, guid_string);
printk(KERN_INFO PREFIX "Skipping duplicate GUID %s\n",
guid_string);
continue;
}
wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
if (!wblock)
return AE_NO_MEMORY;