carl9170 firmware: improve link stability

This patch improves the link stability under load
by reordering and rewriting parts of the tx retry
procedure. It's all based on long hours of trail
and error, but sadly QoS + AMPDU is still not
working.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>

diff --git a/carlfw/src/wlantx.c b/carlfw/src/wlantx.c
index 801086636c861749829d426553848ebc53e9a841..a421c4c0d65ddefdad4d4f2b8ac269f5c2518471 100644 (file)
--- a/carlfw/src/wlantx.c
+++ b/carlfw/src/wlantx.c
@@ -33,15 +33,35 @@
 #include "linux/ieee80211.h"
 #include "wol.h"
 
-static void wlan_txunstuck(unsigned int queue)
+static void wlan_txunstuck(unsigned int qidx)
 {
-       set_wlan_txq_dma_addr(queue, ((uint32_t) fw.wlan.tx_queue[queue].head) | 1);
+       struct dma_queue *queue = &fw.wlan.tx_queue[qidx];
+       struct dma_desc *iter;
+
+       /*
+        * walk up to the last descriptor which hasn't been
+        * processed by the hardware before it bailed out
+        * due to a TX error.
+        * Note: if there was no more "pending" frame
+        * in the queue, it iter will be on the
+        *    queue->terminator (which is fine)
+        */
+       __for_each_desc_bits(iter, queue, AR9170_OWN_BITS_SW);
+
+       set_wlan_txq_dma_addr(qidx, ((uint32_t) iter) | 1);
+       wlan_trigger(BIT(qidx));
 }
 
 #ifdef CONFIG_CARL9170FW_DMA_QUEUE_BUMP
-static void wlan_txupdate(unsigned int queue)
+static void wlan_txupdate(unsigned int qidx)
 {
-       set_wlan_txq_dma_addr(queue, ((uint32_t) fw.wlan.tx_queue[queue].head));
+       struct dma_queue *queue = &fw.wlan.tx_queue[qidx];
+       struct dma_desc *iter;
+       /* comment in wlan_txunstuck applies here too. */
+       __for_each_desc_bits(iter, queue, AR9170_OWN_BITS_SW);
+
+       set_wlan_txq_dma_addr(qidx, ((uint32_t) iter));
+       wlan_trigger(BIT(qidx));
 }
 
 void wlan_dma_bump(unsigned int qidx)
@@ -367,7 +387,7 @@ static bool wlan_tx_status(struct dma_queue *queue,
                                wlan_txunstuck(qidx);
 
                                /* abort cycle - this is necessary due to HW design */
-                               return false;
+                               goto out;
                        } else {
                                /* (HT-) BlockACK failure */
 
@@ -383,7 +403,7 @@ static bool wlan_tx_status(struct dma_queue *queue,
                                BUG_ON(dma_unlink_head(queue) != desc);
 #endif /* CONFIG_CARL9170FW_DEBUG */
                                dma_put(&fw.wlan.tx_retry, desc);
-                               return true;
+                               goto out;
                        }
                } else {
                        /* out of frame attempts - discard frame */
@@ -415,7 +435,7 @@ static bool wlan_tx_status(struct dma_queue *queue,
                if (fw.wlan.fw_desc_callback)
                        fw.wlan.fw_desc_callback(super, success);
 
-               return true;
+               goto out;
        }
 
        if (unlikely(super->s.cab))
@@ -430,7 +450,12 @@ static bool wlan_tx_status(struct dma_queue *queue,
        /* recycle freed descriptors */
        dma_reclaim(&fw.pta.down_queue, desc);
        down_trigger();
-       return true;
+out:
+       /*
+        * if we encounter a frame which run out of (normal)
+        * tx retries we have to stop too.
+        */
+       return !txfail;
 }
 
 void handle_wlan_tx_completion(void)