X86 platform wmi: Introduce debug param to log all WMI events

To give people easily an idea what could be WMI driven on their system.
Introduces:
wmi.debug=[01]

Tested on an acer:
ACPI: WMI: DEBUG Event INTEGER_TYPE - 65535

Situation where a driver registers for specific event and debug
handler gets overridden and set again if the registering driver gets
unloaded again is untested, but should work.

Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: platform-driver-x86@vger.kernel.org
CC: mjg59@srcf.ucam.org
CC: corentin.chary@gmail.com
Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

1 files changed, 50 insertions, 8 deletions

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 17df134a6f03..e820f4cddb61 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -81,6 +81,11 @@ static struct wmi_block wmi_blocks;
 #define ACPI_WMI_STRING      0x4        /* GUID takes & returns a string */
 #define ACPI_WMI_EVENT       0x8        /* GUID is an event */
 
+static int debug_event;
+module_param(debug_event, bool, 0444);
+MODULE_PARM_DESC(debug_event,
+                 "Log WMI Events [0/1]");
+
 static int acpi_wmi_remove(struct acpi_device *device, int type);
 static int acpi_wmi_add(struct acpi_device *device);
 static void acpi_wmi_notify(struct acpi_device *device, u32 event);
@@ -477,6 +482,37 @@ const struct acpi_buffer *in)
 }
 EXPORT_SYMBOL_GPL(wmi_set_block);
 
+static void wmi_notify_debug(u32 value, void *context)
+{
+        struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
+        union acpi_object *obj;
+
+        wmi_get_event_data(value, &response);
+
+        obj = (union acpi_object *)response.pointer;
+
+        if (!obj)
+                return;
+
+        printk(KERN_INFO PREFIX "DEBUG Event ");
+        switch(obj->type) {
+        case ACPI_TYPE_BUFFER:
+                printk("BUFFER_TYPE - length %d\n", obj->buffer.length);
+                break;
+        case ACPI_TYPE_STRING:
+                printk("STRING_TYPE - %s\n", obj->string.pointer);
+                break;
+        case ACPI_TYPE_INTEGER:
+                printk("INTEGER_TYPE - %llu\n", obj->integer.value);
+                break;
+        case ACPI_TYPE_PACKAGE:
+                printk("PACKAGE_TYPE - %d elements\n", obj->package.count);
+                break;
+        default:
+                printk("object type 0x%X\n", obj->type);
+        }
+}
+
 /**
  * wmi_install_notify_handler - Register handler for WMI events
  * @handler: Function to handle notifications
@@ -496,7 +532,7 @@ wmi_notify_handler handler, void *data)
         if (!find_guid(guid, &block))
                 return AE_NOT_EXIST;
 
-        if (block->handler)
+        if (block->handler && block->handler != wmi_notify_debug)
                 return AE_ALREADY_ACQUIRED;
 
         block->handler = handler;
@@ -516,7 +552,7 @@ EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
 acpi_status wmi_remove_notify_handler(const char *guid)
 {
         struct wmi_block *block;
-        acpi_status status;
+        acpi_status status = AE_OK;
 
         if (!guid)
                 return AE_BAD_PARAMETER;
@@ -524,14 +560,16 @@ acpi_status wmi_remove_notify_handler(const char *guid)
         if (!find_guid(guid, &block))
                 return AE_NOT_EXIST;
 
-        if (!block->handler)
+        if (!block->handler || block->handler == wmi_notify_debug)
                 return AE_NULL_ENTRY;
 
-        status = wmi_method_enable(block, 0);
-
-        block->handler = NULL;
-        block->handler_data = NULL;
-
+        if (debug_event) {
+                block->handler = wmi_notify_debug;
+        } else {
+                status = wmi_method_enable(block, 0);
+                block->handler = NULL;
+                block->handler_data = NULL;
+        }
         return status;
 }
 EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
@@ -780,6 +818,10 @@ static __init acpi_status parse_wdg(acpi_handle handle)
 
                 wblock->gblock = gblock[i];
                 wblock->handle = handle;
+                if (debug_event) {
+                        wblock->handler = wmi_notify_debug;
+                        status = wmi_method_enable(wblock, 1);
+                }
                 list_add_tail(&wblock->list, &wmi_blocks.list);
         }