[PATCH 1/3] brcmfmac: calling skb_orphan before sending skb to SDIO bus

[Wright Feng <Wright.Feng@cypress.com>]

Linux 3.6 introduces TSQ which has a per socket threshold for TCP Tx
packets to reduce latency. In fcmode 1 and fcmode 2, host driver enqueues
skb in hanger and TCP doesn't push new skb until host frees the skb when
receiving fwstatus event. So using skb_orphan before sending skb to bus
will make the skb removing the ownership of socket. With this patch, we
are able to get better throughput in fcmode 1 and fcmode 2.

Tested 43455 TCP throughput in 20 MHz bandwidth with / without this patch.
fcmode 0: 59.5 / 59.6 (mbps)
fcmode 1: 59.3 / 23.4 (mbps)
fcmode 2: 59.6 / 21.5 (mbps)

Signed-off-by: Wright Feng <wright.feng@cypress.com>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
index b2e1ab5..519b25d 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
@@ -2298,6 +2298,7 @@ static uint brcmf_sdio_sendfromq(struct brcmf_sdio *bus, uint maxframes)
 					      &prec_out);
 			if (pkt == NULL)
 				break;
+			skb_orphan(pkt);
 			__skb_queue_tail(&pktq, pkt);
 		}
 		spin_unlock_bh(&bus->txq_lock);
-- 
1.9.1