[ 30/89] brcmsmac: handle packet drop during transmit correctly

From: Greg Kroah-Hartman
Date: Fri Feb 01 2013 - 08:10:03 EST


3.7-stable review patch. If anyone has any objections, please let me know.

------------------

From: Piotr Haber <phaber@xxxxxxxxxxxx>

commit c4dea35e34f5f46e1701156153a09cce429d1ea9 upstream.

The .tx() callback function can drop packets when there is no
space in the DMA fifo. Propagate that information to caller
and make sure the freed sk_buff reference is not accessed.

Reviewed-by: Arend van Spriel <arend@xxxxxxxxxxxx>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@xxxxxxxxxxxx>
Signed-off-by: Piotr Haber <phaber@xxxxxxxxxxxx>
Signed-off-by: Arend van Spriel <arend@xxxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c | 4 ++--
drivers/net/wireless/brcm80211/brcmsmac/main.c | 14 +++++++++-----
drivers/net/wireless/brcm80211/brcmsmac/main.h | 2 +-
drivers/net/wireless/brcm80211/brcmsmac/pub.h | 2 +-
4 files changed, 13 insertions(+), 9 deletions(-)

--- a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
@@ -280,8 +280,8 @@ static void brcms_ops_tx(struct ieee8021
kfree_skb(skb);
goto done;
}
- brcms_c_sendpkt_mac80211(wl->wlc, skb, hw);
- tx_info->rate_driver_data[0] = control->sta;
+ if (brcms_c_sendpkt_mac80211(wl->wlc, skb, hw))
+ tx_info->rate_driver_data[0] = control->sta;
done:
spin_unlock_bh(&wl->lock);
}
--- a/drivers/net/wireless/brcm80211/brcmsmac/main.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/main.c
@@ -6095,7 +6095,7 @@ static bool brcms_c_prec_enq(struct brcm
return brcms_c_prec_enq_head(wlc, q, pkt, prec, false);
}

-void brcms_c_txq_enq(struct brcms_c_info *wlc, struct scb *scb,
+bool brcms_c_txq_enq(struct brcms_c_info *wlc, struct scb *scb,
struct sk_buff *sdu, uint prec)
{
struct brcms_txq_info *qi = wlc->pkt_queue; /* Check me */
@@ -6110,7 +6110,9 @@ void brcms_c_txq_enq(struct brcms_c_info
* packet flooding from mac80211 stack
*/
brcmu_pkt_buf_free_skb(sdu);
+ return false;
}
+ return true;
}

/*
@@ -7273,7 +7275,7 @@ brcms_c_d11hdrs_mac80211(struct brcms_c_
return 0;
}

-void brcms_c_sendpkt_mac80211(struct brcms_c_info *wlc, struct sk_buff *sdu,
+bool brcms_c_sendpkt_mac80211(struct brcms_c_info *wlc, struct sk_buff *sdu,
struct ieee80211_hw *hw)
{
u8 prio;
@@ -7288,10 +7290,12 @@ void brcms_c_sendpkt_mac80211(struct brc
prio = ieee80211_is_data(d11_header->frame_control) ? sdu->priority :
MAXPRIO;
fifo = prio2fifo[prio];
- if (brcms_c_d11hdrs_mac80211(wlc, hw, sdu, scb, 0, 1, fifo, 0))
- return;
- brcms_c_txq_enq(wlc, scb, sdu, BRCMS_PRIO_TO_PREC(prio));
+ brcms_c_d11hdrs_mac80211(wlc, hw, sdu, scb, 0, 1, fifo, 0);
+ if (!brcms_c_txq_enq(wlc, scb, sdu, BRCMS_PRIO_TO_PREC(prio)))
+ return false;
brcms_c_send_q(wlc);
+
+ return true;
}

void brcms_c_send_q(struct brcms_c_info *wlc)
--- a/drivers/net/wireless/brcm80211/brcmsmac/main.h
+++ b/drivers/net/wireless/brcm80211/brcmsmac/main.h
@@ -642,7 +642,7 @@ extern void brcms_c_txfifo(struct brcms_
bool commit, s8 txpktpend);
extern void brcms_c_txfifo_complete(struct brcms_c_info *wlc, uint fifo,
s8 txpktpend);
-extern void brcms_c_txq_enq(struct brcms_c_info *wlc, struct scb *scb,
+extern bool brcms_c_txq_enq(struct brcms_c_info *wlc, struct scb *scb,
struct sk_buff *sdu, uint prec);
extern void brcms_c_print_txstatus(struct tx_status *txs);
extern int brcms_b_xmtfifo_sz_get(struct brcms_hardware *wlc_hw, uint fifo,
--- a/drivers/net/wireless/brcm80211/brcmsmac/pub.h
+++ b/drivers/net/wireless/brcm80211/brcmsmac/pub.h
@@ -321,7 +321,7 @@ extern void brcms_c_intrsrestore(struct
extern bool brcms_c_intrsupd(struct brcms_c_info *wlc);
extern bool brcms_c_isr(struct brcms_c_info *wlc, bool *wantdpc);
extern bool brcms_c_dpc(struct brcms_c_info *wlc, bool bounded);
-extern void brcms_c_sendpkt_mac80211(struct brcms_c_info *wlc,
+extern bool brcms_c_sendpkt_mac80211(struct brcms_c_info *wlc,
struct sk_buff *sdu,
struct ieee80211_hw *hw);
extern bool brcms_c_aggregatable(struct brcms_c_info *wlc, u8 tid);


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