mac80211: remove TX latency measurement code

Revert commit ad38bfc916da ("mac80211: Tx frame latency statistics")
(along with some follow-up fixes).

This code turned out not to be as useful in the current form as we
thought, and we've internally hacked it up more, but that's not
very suitable for upstream (for now), and we might just do that
with tracing instead.

Therefore, for now at least, remove this code. We might also need
to use the skb->tstamp field for the TCP performance issue, which
is more important than the debugging.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 0 insertions, 134 deletions

diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index 94c70091bbd7..252859e90e8a 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -39,13 +39,6 @@ static const struct file_operations sta_ ##name## _ops = {		\
         .llseek = generic_file_llseek,                                  \
 }
 
-#define STA_OPS_W(name)                                                 \
-static const struct file_operations sta_ ##name## _ops = {              \
-        .write = sta_##name##_write,                                    \
-        .open = simple_open,                                            \
-        .llseek = generic_file_llseek,                                  \
-}
-
 #define STA_OPS_RW(name)                                                \
 static const struct file_operations sta_ ##name## _ops = {              \
         .read = sta_##name##_read,                                      \
@@ -398,131 +391,6 @@ static ssize_t sta_last_rx_rate_read(struct file *file, char __user *userbuf,
 }
 STA_OPS(last_rx_rate);
 
-static int
-sta_tx_latency_stat_header(struct ieee80211_tx_latency_bin_ranges *tx_latency,
-                           char *buf, int pos, int bufsz)
-{
-        int i;
-        int range_count = tx_latency->n_ranges;
-        u32 *bin_ranges = tx_latency->ranges;
-
-        pos += scnprintf(buf + pos, bufsz - pos,
-                          "Station\t\t\tTID\tMax\tAvg");
-        if (range_count) {
-                pos += scnprintf(buf + pos, bufsz - pos,
-                                  "\t<=%d", bin_ranges[0]);
-                for (i = 0; i < range_count - 1; i++)
-                        pos += scnprintf(buf + pos, bufsz - pos, "\t%d-%d",
-                                          bin_ranges[i], bin_ranges[i+1]);
-                pos += scnprintf(buf + pos, bufsz - pos,
-                                  "\t%d<", bin_ranges[range_count - 1]);
-        }
-
-        pos += scnprintf(buf + pos, bufsz - pos, "\n");
-
-        return pos;
-}
-
-static int
-sta_tx_latency_stat_table(struct ieee80211_tx_latency_bin_ranges *tx_lat_range,
-                          struct ieee80211_tx_latency_stat *tx_lat,
-                          char *buf, int pos, int bufsz, int tid)
-{
-        u32 avg = 0;
-        int j;
-        int bin_count = tx_lat->bin_count;
-
-        pos += scnprintf(buf + pos, bufsz - pos, "\t\t\t%d", tid);
-        /* make sure you don't divide in 0 */
-        if (tx_lat->counter)
-                avg = tx_lat->sum / tx_lat->counter;
-
-        pos += scnprintf(buf + pos, bufsz - pos, "\t%d\t%d",
-                          tx_lat->max, avg);
-
-        if (tx_lat_range->n_ranges && tx_lat->bins)
-                for (j = 0; j < bin_count; j++)
-                        pos += scnprintf(buf + pos, bufsz - pos,
-                                          "\t%d", tx_lat->bins[j]);
-        pos += scnprintf(buf + pos, bufsz - pos, "\n");
-
-        return pos;
-}
-
-/*
- * Output Tx latency statistics station && restart all statistics information
- */
-static ssize_t sta_tx_latency_stat_read(struct file *file,
-                                        char __user *userbuf,
-                                        size_t count, loff_t *ppos)
-{
-        struct sta_info *sta = file->private_data;
-        struct ieee80211_local *local = sta->local;
-        struct ieee80211_tx_latency_bin_ranges *tx_latency;
-        char *buf;
-        int bufsz, ret, i;
-        int pos = 0;
-
-        bufsz = 20 * IEEE80211_NUM_TIDS *
-                sizeof(struct ieee80211_tx_latency_stat);
-        buf = kzalloc(bufsz, GFP_KERNEL);
-        if (!buf)
-                return -ENOMEM;
-
-        rcu_read_lock();
-
-        tx_latency = rcu_dereference(local->tx_latency);
-
-        if (!sta->tx_lat) {
-                pos += scnprintf(buf + pos, bufsz - pos,
-                                 "Tx latency statistics are not enabled\n");
-                goto unlock;
-        }
-
-        pos = sta_tx_latency_stat_header(tx_latency, buf, pos, bufsz);
-
-        pos += scnprintf(buf + pos, bufsz - pos, "%pM\n", sta->sta.addr);
-        for (i = 0; i < IEEE80211_NUM_TIDS; i++)
-                pos = sta_tx_latency_stat_table(tx_latency, &sta->tx_lat[i],
-                                                buf, pos, bufsz, i);
-unlock:
-        rcu_read_unlock();
-
-        ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
-        kfree(buf);
-
-        return ret;
-}
-STA_OPS(tx_latency_stat);
-
-static ssize_t sta_tx_latency_stat_reset_write(struct file *file,
-                                               const char __user *userbuf,
-                                               size_t count, loff_t *ppos)
-{
-        u32 *bins;
-        int bin_count;
-        struct sta_info *sta = file->private_data;
-        int i;
-
-        if (!sta->tx_lat)
-                return -EINVAL;
-
-        for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
-                bins = sta->tx_lat[i].bins;
-                bin_count = sta->tx_lat[i].bin_count;
-
-                sta->tx_lat[i].max = 0;
-                sta->tx_lat[i].sum = 0;
-                sta->tx_lat[i].counter = 0;
-
-                if (bin_count)
-                        memset(bins, 0, bin_count * sizeof(u32));
-        }
-
-        return count;
-}
-STA_OPS_W(tx_latency_stat_reset);
-
 #define DEBUGFS_ADD(name) \
         debugfs_create_file(#name, 0400, \
                 sta->debugfs.dir, sta, &sta_ ##name## _ops);
@@ -576,8 +444,6 @@ void ieee80211_sta_debugfs_add(struct sta_info *sta)
         DEBUGFS_ADD(last_ack_signal);
         DEBUGFS_ADD(current_tx_rate);
         DEBUGFS_ADD(last_rx_rate);
-        DEBUGFS_ADD(tx_latency_stat);
-        DEBUGFS_ADD(tx_latency_stat_reset);
 
         DEBUGFS_ADD_COUNTER(rx_packets, rx_packets);
         DEBUGFS_ADD_COUNTER(tx_packets, tx_packets);