carl9170: fix HT peer BA session corruption

This patch adds an alternative tx status path
for BlockAck Requests as the hardware doesn't
recognize that a BlockAck Requests is usually
acked with a BlockAck and not a legacy ACK.

Without this patch, the stack would constantly
resent old and stale BARs. So, depending on the
receiver stack, this could lead to:

 - "stuck" ba sessions and package loss, as the
   stale BAR would reset the sequence each time.

 - lots of reorder releases.

 - ...

Reported-by: Sean Patrick Santos <quantheory@gmail.com>
Reported-by: Mikołaj Kuligowski <mikolaj.q@wp.pl>
Reported-by: Per-Erik Westerberg <per-erik.westerberg@bredband.net>
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/carl9170/carl9170.h b/drivers/net/wireless/ath/carl9170/carl9170.h
index 0cea20e3e250..376be11161c0 100644
--- a/drivers/net/wireless/ath/carl9170/carl9170.h
+++ b/drivers/net/wireless/ath/carl9170/carl9170.h
@@ -289,6 +289,7 @@ struct ar9170 {
 		unsigned int mem_block_size;
 		unsigned int rx_size;
 		unsigned int tx_seq_table;
+		bool ba_filter;
 	} fw;
 
 	/* interface configuration combinations */
@@ -425,6 +426,10 @@ struct ar9170 {
 	struct sk_buff *rx_failover;
 	int rx_failover_missing;
 
+	/* FIFO for collecting outstanding BlockAckRequest */
+	struct list_head bar_list[__AR9170_NUM_TXQ];
+	spinlock_t bar_list_lock[__AR9170_NUM_TXQ];
+
 #ifdef CONFIG_CARL9170_WPC
 	struct {
 		bool pbc_state;
@@ -468,6 +473,12 @@ enum carl9170_ps_off_override_reasons {
 	PS_OFF_BCN	= BIT(1),
 };
 
+struct carl9170_bar_list_entry {
+	struct list_head list;
+	struct rcu_head head;
+	struct sk_buff *skb;
+};
+
 struct carl9170_ba_stats {
 	u8 ampdu_len;
 	u8 ampdu_ack_len;