iwlwifi: add FIFO usage for 5000

This is part of the code, but the comment doesn't have it,
add pointers to the code and the FIFO usage for 5000 and
up.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-prph.h

@@ -254,7 +254,8 @@
  * device.  A queue maps to only one (selectable by driver) Tx DMA channel,
  * but one DMA channel may take input from several queues.
  *
- * Tx DMA channels have dedicated purposes.  For 4965, they are used as follows:
+ * Tx DMA channels have dedicated purposes.  For 4965, they are used as follows
+ * (cf. default_queue_to_tx_fifo in iwl-4965.c):
  *
  * 0 -- EDCA BK (background) frames, lowest priority
  * 1 -- EDCA BE (best effort) frames, normal priority
@@ -265,9 +266,21 @@
  * 6 -- HCCA long frames
  * 7 -- not used by driver (device-internal only)
  *
+ * For 5000 series and up, they are used slightly differently
+ * (cf. iwl5000_default_queue_to_tx_fifo in iwl-5000.c):
+ *
+ * 0 -- EDCA BK (background) frames, lowest priority
+ * 1 -- EDCA BE (best effort) frames, normal priority
+ * 2 -- EDCA VI (video) frames, higher priority
+ * 3 -- EDCA VO (voice) and management frames, highest priority
+ * 4 -- (TBD)
+ * 5 -- HCCA short frames
+ * 6 -- HCCA long frames
+ * 7 -- Commands
+ *
  * Driver should normally map queues 0-6 to Tx DMA/FIFO channels 0-6.
- * In addition, driver can map queues 7-15 to Tx DMA/FIFO channels 0-3 to
- * support 11n aggregation via EDCA DMA channels.
+ * In addition, driver can map the remaining queues to Tx DMA/FIFO
+ * channels 0-3 to support 11n aggregation via EDCA DMA channels.
  *
  * The driver sets up each queue to work in one of two modes:
  *