minstrel_ht: fixed rate mode through debugfs

Found several threads about fixed rate mode in minstrel_ht for test
environments, but no patches for it.

This patch provides such a mode through debugfs.

Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 28 insertions, 0 deletions

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 8adac67395f7..58a89554b788 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -532,12 +532,21 @@ minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
         mp->hw = hw;
         mp->update_interval = 100;
 
+#ifdef CONFIG_MAC80211_DEBUGFS
+        mp->fixed_rate_idx = (u32) -1;
+        mp->dbg_fixed_rate = debugfs_create_u32("fixed_rate_idx",
+                        S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx);
+#endif
+
         return mp;
 }
 
 static void
 minstrel_free(void *priv)
 {
+#ifdef CONFIG_MAC80211_DEBUGFS
+        debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate);
+#endif
         kfree(priv);
 }
 
diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 0f5a83370aa6..5d278eccaef0 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -78,6 +78,18 @@ struct minstrel_priv {
         unsigned int update_interval;
         unsigned int lookaround_rate;
         unsigned int lookaround_rate_mrr;
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+        /*
+         * enable fixed rate processing per RC
+         *   - write static index to debugfs:ieee80211/phyX/rc/fixed_rate_idx
+         *   - write -1 to enable RC processing again
+         *   - setting will be applied on next update
+         */
+        u32 fixed_rate_idx;
+        struct dentry *dbg_fixed_rate;
+#endif
+
 };
 
 struct minstrel_debugfs_info {
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 333b5118be6d..66a1eeb279c6 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -609,6 +609,13 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
 
         info->flags |= mi->tx_flags;
         sample_idx = minstrel_get_sample_rate(mp, mi);
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+        /* use fixed index if set */
+        if (mp->fixed_rate_idx != -1)
+                sample_idx = mp->fixed_rate_idx;
+#endif
+
         if (sample_idx >= 0) {
                 sample = true;
                 minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,