ACPI / tables: improve comments regarding acpi_parse_entries_array()

I found the description of the table_size argument to the function
acpi_parse_entries_array() unclear and ambiguous.  This is a minor
documentation change to improve that description so I don't misuse
the argument again in the future, and it is hopefully clearer to
other future users.

Signed-off-by: Al Stone <ahs3@redhat.com>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/tables.c

@@ -222,7 +222,7 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
  * acpi_parse_entries_array - for each proc_num find a suitable subtable
  *
  * @id: table id (for debugging purposes)
- * @table_size: single entry size
+ * @table_size: size of the root table
  * @table_header: where does the table start?
  * @proc: array of acpi_subtable_proc struct containing entry id
  *        and associated handler with it
@@ -233,6 +233,11 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
  * on it. Assumption is that there's only single handler for particular
  * entry id.
  *
+ * The table_size is not the size of the complete ACPI table (the length
+ * field in the header struct), but only the size of the root table; i.e.,
+ * the offset from the very first byte of the complete ACPI table, to the
+ * first byte of the very first subtable.
+ *
  * On success returns sum of all matching entries for all proc handlers.
  * Otherwise, -ENODEV or -EINVAL is returned.
  */
@@ -400,7 +405,7 @@ int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
 		return -ENODEV;
 }
 
-/* 
+/*
  * The BIOS is supposed to supply a single APIC/MADT,
  * but some report two.  Provide a knob to use either.
  * (don't you wish instance 0 and 1 were not the same?)