cfg80211/mac80211: Use more generic bitrate mask for rate control

Extend struct cfg80211_bitrate_mask to actually use a bitfield mask
instead of just a single fixed or maximum rate index. This change
itself does not modify the behavior (except for debugfs files), but it
prepares cfg80211 and mac80211 for a new nl80211 command for setting
which rates can be used in TX rate control.

Since frames are now going through the rate control algorithm
unconditionally, the internal IEEE80211_TX_INTFL_RCALGO flag can now
be removed. The RC implementations can use the rate_idx_mask value to
optimize their behavior if only a single rate is enabled.

The old max_rate_idx in struct ieee80211_tx_rate_control is maintained
(but commented as deprecated) for backwards compatibility with existing
RC implementations. Once these implementations have been updated to
use the more generic rate_idx_mask, the max_rate_idx value can be
removed.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 2 insertions, 11 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index a8d5d04314b9..22e062afb5a1 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -857,20 +857,11 @@ enum tx_power_setting {
  * cfg80211_bitrate_mask - masks for bitrate control
  */
 struct cfg80211_bitrate_mask {
-/*
- * As discussed in Berlin, this struct really
- * should look like this:
-
 	struct {
 		u32 legacy;
-		u8 mcs[IEEE80211_HT_MCS_MASK_LEN];
+		/* TODO: add support for masking MCS rates; e.g.: */
+		/* u8 mcs[IEEE80211_HT_MCS_MASK_LEN]; */
 	} control[IEEE80211_NUM_BANDS];
-
- * Since we can always fix in-kernel users, let's keep
- * it simpler for now:
- */
-	u32 fixed;   /* fixed bitrate, 0 == not fixed */
-	u32 maxrate; /* in kbps, 0 == no limit */
 };
 /**
  * struct cfg80211_pmksa - PMK Security Association