From ee0591b9b8d0a42f60eae6f9c644e6a1be4323d6 Mon Sep 17 00:00:00 2001
From: Peter Wu <lekensteyn@gmail.com>
Date: Wed, 31 Jul 2013 21:31:07 +0200
Subject: [PATCH] Clarify why Buffer is used instead of Package

---
 bbswitch.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/bbswitch.c b/bbswitch.c
index 5c85c10..30fbf94 100644
--- a/bbswitch.c
+++ b/bbswitch.c
@@ -120,6 +120,9 @@ static int acpi_call_dsm(acpi_handle handle, const char muid[16], int revid,
     params[1].integer.value = revid;
     params[2].type = ACPI_TYPE_INTEGER;
     params[2].integer.value = func;
+    /* Although the ACPI spec defines Arg3 as a Package, in practise
+     * implementations expect a Buffer (CreateWordField and Index functions are
+     * applied to it). */
     params[3].type = ACPI_TYPE_BUFFER;
     params[3].buffer.length = 4;
     if (args) {