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, 49 insertions, 11 deletions

diff --git a/drivers/net/wireless/b43/xmit.c b/drivers/net/wireless/b43/xmit.c
index 2fabcf8f047..adba89b816d 100644
--- a/drivers/net/wireless/b43/xmit.c
+++ b/drivers/net/wireless/b43/xmit.c
@@ -185,7 +185,7 @@ int b43_generate_txhdr(struct b43_wldev *dev,
                        u8 *_txhdr,
                        const unsigned char *fragment_data,
                        unsigned int fragment_len,
-                       const struct ieee80211_tx_info *info,
+                       struct ieee80211_tx_info *info,
                        u16 cookie)
 {
         struct b43_txhdr *txhdr = (struct b43_txhdr *)_txhdr;
@@ -202,6 +202,7 @@ int b43_generate_txhdr(struct b43_wldev *dev,
         u16 phy_ctl = 0;
         u8 extra_ft = 0;
         struct ieee80211_rate *txrate;
+        struct ieee80211_tx_rate *rates;
 
         memset(txhdr, 0, sizeof(*txhdr));
 
@@ -291,7 +292,7 @@ int b43_generate_txhdr(struct b43_wldev *dev,
                 phy_ctl |= B43_TXH_PHY_ENC_OFDM;
         else
                 phy_ctl |= B43_TXH_PHY_ENC_CCK;
-        if (info->flags & IEEE80211_TX_CTL_SHORT_PREAMBLE)
+        if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
                 phy_ctl |= B43_TXH_PHY_SHORTPRMBL;
 
         switch (b43_ieee80211_antenna_sanitize(dev, info->antenna_sel_tx)) {
@@ -314,6 +315,7 @@ int b43_generate_txhdr(struct b43_wldev *dev,
                 B43_WARN_ON(1);
         }
 
+        rates = info->control.rates;
         /* MAC control */
         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
                 mac_ctl |= B43_TXH_MAC_ACK;
@@ -324,12 +326,22 @@ int b43_generate_txhdr(struct b43_wldev *dev,
                 mac_ctl |= B43_TXH_MAC_STMSDU;
         if (phy->type == B43_PHYTYPE_A)
                 mac_ctl |= B43_TXH_MAC_5GHZ;
-        if (info->flags & IEEE80211_TX_CTL_LONG_RETRY_LIMIT)
+
+        /* Overwrite rates[0].count to make the retry calculation
+         * in the tx status easier. need the actual retry limit to
+         * detect whether the fallback rate was used.
+         */
+        if ((rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
+            (rates[0].count <= dev->wl->hw->conf.long_frame_max_tx_count)) {
+                rates[0].count = dev->wl->hw->conf.long_frame_max_tx_count;
                 mac_ctl |= B43_TXH_MAC_LONGFRAME;
+        } else {
+                rates[0].count = dev->wl->hw->conf.short_frame_max_tx_count;
+        }
 
         /* Generate the RTS or CTS-to-self frame */
-        if ((info->flags & IEEE80211_TX_CTL_USE_RTS_CTS) ||
-            (info->flags & IEEE80211_TX_CTL_USE_CTS_PROTECT)) {
+        if ((rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
+            (rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)) {
                 unsigned int len;
                 struct ieee80211_hdr *hdr;
                 int rts_rate, rts_rate_fb;
@@ -344,7 +356,7 @@ int b43_generate_txhdr(struct b43_wldev *dev,
                 rts_rate_fb = b43_calc_fallback_rate(rts_rate);
                 rts_rate_fb_ofdm = b43_is_ofdm_rate(rts_rate_fb);
 
-                if (info->flags & IEEE80211_TX_CTL_USE_CTS_PROTECT) {
+                if (rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT) {
                         struct ieee80211_cts *cts;
 
                         if (b43_is_old_txhdr_format(dev)) {
@@ -687,10 +699,18 @@ void b43_handle_txstatus(struct b43_wldev *dev,
 /* Fill out the mac80211 TXstatus report based on the b43-specific
  * txstatus report data. This returns a boolean whether the frame was
  * successfully transmitted. */
-bool b43_fill_txstatus_report(struct ieee80211_tx_info *report,
+bool b43_fill_txstatus_report(struct b43_wldev *dev,
+                              struct ieee80211_tx_info *report,
                               const struct b43_txstatus *status)
 {
         bool frame_success = 1;
+        int retry_limit;
+
+        /* 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 = report->status.rates[0].count;
+        ieee80211_tx_info_clear_status(report);
 
         if (status->acked) {
                 /* The frame was ACKed. */
@@ -700,14 +720,32 @@ bool b43_fill_txstatus_report(struct ieee80211_tx_info *report,
                 if (!(report->flags & IEEE80211_TX_CTL_NO_ACK)) {
                         /* ...but we expected an ACK. */
                         frame_success = 0;
-                        report->status.excessive_retries = 1;
                 }
         }
         if (status->frame_count == 0) {
                 /* The frame was not transmitted at all. */
-                report->status.retry_count = 0;
-        } else
-                report->status.retry_count = status->frame_count - 1;
+                report->status.rates[0].count = 0;
+        } else 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.
+                 */
+                report->status.rates[0].count = 0;
+                report->status.rates[1].count = status->frame_count;
+        } else {
+                if (status->frame_count > retry_limit) {
+                        report->status.rates[0].count = retry_limit;
+                        report->status.rates[1].count = status->frame_count -
+                                        retry_limit;
+
+                } else {
+                        report->status.rates[0].count = status->frame_count;
+                        report->status.rates[1].idx = -1;
+                }
+        }
 
         return frame_success;
 }