brcmsmac: Remove internal tx queue

The brcmsmac internal tx buffering is problematic. The amount of
buffering is excessive (228 packets in addition to the 256 slots in each
DMA ring), and frames may be dropped due to a lack of flow control.

This patch reworks the transmit code path to remove the internal
buffering. Frames are immediately handed off to the DMA support rather
than passing through an intermediate queue. Non-aggregate frames are
queued immediately into the tx rings, and aggregate frames are queued
temporarily in an AMPDU session until ready for transmit.

Transmit flow control is also added to avoid dropping packets when the
tx rings are full. Conceptually this is a separate change, but it's
included in this commit because removing the tx queue without adding
flow control could cause significant problems.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Tested-by: Daniel Wagner <wagi@monom.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 0 insertions, 3 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmsmac/ampdu.h b/drivers/net/wireless/brcm80211/brcmsmac/ampdu.h
index 9a94923f850..73d01e58610 100644
--- a/drivers/net/wireless/brcm80211/brcmsmac/ampdu.h
+++ b/drivers/net/wireless/brcm80211/brcmsmac/ampdu.h
@@ -45,9 +45,6 @@ extern void brcms_c_ampdu_finalize(struct brcms_ampdu_session *session);
 
 extern struct ampdu_info *brcms_c_ampdu_attach(struct brcms_c_info *wlc);
 extern void brcms_c_ampdu_detach(struct ampdu_info *ampdu);
-extern int brcms_c_sendampdu(struct ampdu_info *ampdu,
-			     struct brcms_txq_info *qi,
-			     struct sk_buff **aggp, int prec);
 extern void brcms_c_ampdu_dotxstatus(struct ampdu_info *ampdu, struct scb *scb,
 				 struct sk_buff *p, struct tx_status *txs);
 extern void brcms_c_ampdu_macaddr_upd(struct brcms_c_info *wlc);