x86 platform drivers: hp-wmi fix buffer size depending on ACPI version

Depending on ACPI version (1.0 -> 32 bit) an integer could be
32 or 64 bit long. _WED internal concatenates two integers and
the return value will be 8 byte (2* 32 bit) or 16 byte (2* 64 bit)
long, depending on the ACPI version.

Also the data send with the WMI event is defined to be splitted into:
  - Event ID -> 4 bytes
  - Event Data -> 4 bytes

This gets messed up with new ACPI versions.
But it's a HP BIOS bug that may get fixed in the future
-> Support both, 16 and 8 byte _WED buffers.

Also the wrong assumption that from the event data sent, only the
first byte is relevant got cleaned up that it fits event_id/event_data
as described above.

Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: robert.moore@intel.com
Signed-off-by: Matthew Garrett <mjg@redhat.com>
CC: platform-driver-x86@vger.kernel.org
CC: linux-acpi@vger.kernel.org

diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
index cd445019a6b7b6629b171de20101629d0cda8f2b..7ebe46fe396ef8436cdf239f1bfe7c12d3c5636a 100644 (file)
--- a/drivers/platform/x86/hp-wmi.c
+++ b/drivers/platform/x86/hp-wmi.c
@@ -352,7 +352,9 @@ static void hp_wmi_notify(u32 value, void *context)
        struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
        static struct key_entry *key;
        union acpi_object *obj;
-       int eventcode, key_code;
+       u32 event_id, event_data;
+       int key_code;
+       u32 *location;
        acpi_status status;
 
        status = wmi_get_event_data(value, &response);
@@ -363,15 +365,33 @@ static void hp_wmi_notify(u32 value, void *context)
 
        obj = (union acpi_object *)response.pointer;
 
-       if (!obj || obj->type != ACPI_TYPE_BUFFER || obj->buffer.length != 8) {
-               printk(KERN_INFO PREFIX "Unknown response received\n");
+       if (obj || obj->type != ACPI_TYPE_BUFFER) {
+               printk(KERN_INFO "hp-wmi: Unknown response received %d\n",
+                      obj->type);
                kfree(obj);
                return;
        }
 
-       eventcode = *((u8 *) obj->buffer.pointer);
+       /*
+        * Depending on ACPI version the concatenation of id and event data
+        * inside _WED function will result in a 8 or 16 byte buffer.
+        */
+       location = (u32 *)obj->buffer.pointer;
+       if (obj->buffer.length == 8) {
+               event_id = *location;
+               event_data = *(location + 1);
+       } else if (obj->buffer.length == 16) {
+               event_id = *location;
+               event_data = *(location + 2);
+       } else {
+               printk(KERN_INFO "hp-wmi: Unknown buffer length %d\n",
+                      obj->buffer.length);
+               kfree(obj);
+               return;
+       }
        kfree(obj);
-       switch (eventcode) {
+
+       switch (event_id) {
        case HPWMI_DOCK_EVENT:
                input_report_switch(hp_wmi_input_dev, SW_DOCK,
                                    hp_wmi_dock_state());
@@ -423,8 +443,8 @@ static void hp_wmi_notify(u32 value, void *context)
        case HPWMI_LOCK_SWITCH:
                break;
        default:
-               printk(KERN_INFO PREFIX "Unknown eventcode - %d\n",
-                      eventcode);
+               printk(KERN_INFO PREFIX "Unknown event_id - %d - 0x%x\n",
+                      event_id, event_data);
                break;
        }
 }