[PATCH] ACPI: WMI: Handle duplicate GUIDs

Carlos Corbacho
2009-12-26T19:15:04Z

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).

Fixes kernel bugzilla #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>
---
Len,

Can you get this out ASAP, as it fixes a regression with the WMI autoloading code.

drivers/platform/x86/wmi.c | 30 ++++++++++++++++++++++++++++++
1 files changed, 30 insertions(+), 0 deletions(-)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 9f93d6c..845aaf6 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -716,6 +716,22 @@ 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
*/
@@ -725,6 +741,7 @@ 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;

@@ -747,6 +764,19 @@ 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;
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html