mac80211/drivers: rewrite the rate control API

So after the previous changes we were still unhappy with how
convoluted the API is and decided to make things simpler for
everybody. This completely changes the rate control API, now
taking into account 802.11n with MCS rates and more control,
most drivers don't support that though.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 32 insertions, 14 deletions

diff --git a/drivers/net/wireless/b43legacy/dma.c b/drivers/net/wireless/b43legacy/dma.c
index fb6819e40f38..308c2647f002 100644
--- a/drivers/net/wireless/b43legacy/dma.c
+++ b/drivers/net/wireless/b43legacy/dma.c
@@ -1411,6 +1411,7 @@ void b43legacy_dma_handle_txstatus(struct b43legacy_wldev *dev,
         struct b43legacy_dmaring *ring;
         struct b43legacy_dmadesc_generic *desc;
         struct b43legacy_dmadesc_meta *meta;
+        int retry_limit;
         int slot;
 
         ring = parse_cookie(dev, status->cookie, &slot);
@@ -1437,25 +1438,42 @@ void b43legacy_dma_handle_txstatus(struct b43legacy_wldev *dev,
                         struct ieee80211_tx_info *info;
                         BUG_ON(!meta->skb);
                         info = IEEE80211_SKB_CB(meta->skb);
-                        /* Call back to inform the ieee80211 subsystem about the
-                         * status of the transmission.
-                         * Some fields of txstat are already filled in dma_tx().
-                         */
 
-                        memset(&info->status, 0, sizeof(info->status));
+                        /* preserve the confiured retry limit before clearing the status
+                         * The xmit function has overwritten the rc's value with the actual
+                         * retry limit done by the hardware */
+                        retry_limit = info->status.rates[0].count;
+                        ieee80211_tx_info_clear_status(info);
 
-                        if (status->acked) {
+                        if (status->acked)
                                 info->flags |= IEEE80211_TX_STAT_ACK;
+
+                        if (status->rts_count > dev->wl->hw->conf.short_frame_max_tx_count) {
+                                /*
+                                 * If the short retries (RTS, not data frame) have exceeded
+                                 * the limit, the hw will not have tried the selected rate,
+                                 * but will have used the fallback rate instead.
+                                 * Don't let the rate control count attempts for the selected
+                                 * rate in this case, otherwise the statistics will be off.
+                                 */
+                                info->status.rates[0].count = 0;
+                                info->status.rates[1].count = status->frame_count;
                         } else {
-                                if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
-                                         info->status.excessive_retries = 1;
+                                if (status->frame_count > retry_limit) {
+                                        info->status.rates[0].count = retry_limit;
+                                        info->status.rates[1].count = status->frame_count -
+                                                        retry_limit;
+
+                                } else {
+                                        info->status.rates[0].count = status->frame_count;
+                                        info->status.rates[1].idx = -1;
+                                }
                         }
-                        if (status->frame_count == 0) {
-                                /* The frame was not transmitted at all. */
-                                info->status.retry_count = 0;
-                        } else
-                                info->status.retry_count = status->frame_count
-                                                           - 1;
+
+                        /* Call back to inform the ieee80211 subsystem about the
+                         * status of the transmission.
+                         * Some fields of txstat are already filled in dma_tx().
+                         */
                         ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb);
                         /* skb is freed by ieee80211_tx_status_irqsafe() */
                         meta->skb = NULL;