brcm80211: smac: fix endless retry of A-MPDU transmissions

The A-MPDU code checked against a retry limit, but it was using
the wrong variable to do so. This patch fixes this to assure
proper retry mechanism.

This problem had a side-effect causing the mac80211 flush callback
to remain waiting forever as well. That side effect has been fixed
by commit by Stanislaw Gruszka:

commit f96b08a7
Date:   Tue Jan 17 12:38:50 2012 +0100

    brcmsmac: fix tx queue flush infinite loop

    Reference:
    https://bugzilla.kernel.org/show_bug.cgi?id=42576

Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Alwin Beukers <alwin@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/brcm80211/brcmsmac/ampdu.c

@@ -1051,17 +1051,13 @@ brcms_c_ampdu_dotxstatus_complete(struct ampdu_info *ampdu, struct scb *scb,
 		}
 		/* either retransmit or send bar if ack not recd */
 		if (!ack_recd) {
-			struct ieee80211_tx_rate *txrate =
-			    tx_info->status.rates;
-			if (retry && (txrate[0].count < (int)retry_limit)) {
+			if (retry && (ini->txretry[index] < (int)retry_limit)) {
 				ini->txretry[index]++;
 				ini->tx_in_transit--;
 				/*
 				 * Use high prededence for retransmit to
 				 * give some punch
 				 */
-				/* brcms_c_txq_enq(wlc, scb, p,
-				 * BRCMS_PRIO_TO_PREC(tid)); */
 				brcms_c_txq_enq(wlc, scb, p,
 						BRCMS_PRIO_TO_HI_PREC(tid));
 			} else {