Ath5k: lock beacons

Beacons setup and config was racy with beacon send. Ensure that
ISR and reset functions see consistent state of bbuf.

Use also dev_kfree_skb_any in ath5k_txbuf_free since we call it
from atomic now.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Nick Kossifidis <mickflemm@gmail.com>
Cc: Luis R. Rodriguez <mcgrof@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 13 insertions, 3 deletions

diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c
index b20a45aa8680..7bc012fca059 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -251,7 +251,7 @@ static inline void ath5k_txbuf_free(struct ath5k_softc *sc,
                 return;
         pci_unmap_single(sc->pdev, bf->skbaddr, bf->skb->len,
                         PCI_DMA_TODEVICE);
-        dev_kfree_skb(bf->skb);
+        dev_kfree_skb_any(bf->skb);
         bf->skb = NULL;
 }
 
@@ -466,6 +466,7 @@ ath5k_pci_probe(struct pci_dev *pdev,
         mutex_init(&sc->lock);
         spin_lock_init(&sc->rxbuflock);
         spin_lock_init(&sc->txbuflock);
+        spin_lock_init(&sc->block);
 
         /* Set private data */
         pci_set_drvdata(pdev, hw);
@@ -2179,8 +2180,11 @@ ath5k_beacon_config(struct ath5k_softc *sc)
 
                 sc->imask |= AR5K_INT_SWBA;
 
-                if (ath5k_hw_hasveol(ah))
+                if (ath5k_hw_hasveol(ah)) {
+                        spin_lock(&sc->block);
                         ath5k_beacon_send(sc);
+                        spin_unlock(&sc->block);
+                }
         }
         /* TODO else AP */
 
@@ -2403,7 +2407,9 @@ ath5k_intr(int irq, void *dev_id)
                                                   TSF_TO_TU(tsf),
                                                   (unsigned long long) tsf);
                                 } else {
+                                        spin_lock(&sc->block);
                                         ath5k_beacon_send(sc);
+                                        spin_unlock(&sc->block);
                                 }
                         }
                         if (status & AR5K_INT_RXEOL) {
@@ -3050,6 +3056,7 @@ static int
 ath5k_beacon_update(struct ieee80211_hw *hw, struct sk_buff *skb)
 {
         struct ath5k_softc *sc = hw->priv;
+        unsigned long flags;
         int ret;
 
         ath5k_debug_dump_skb(sc, skb, "BC  ", 1);
@@ -3059,12 +3066,14 @@ ath5k_beacon_update(struct ieee80211_hw *hw, struct sk_buff *skb)
                 goto end;
         }
 
+        spin_lock_irqsave(&sc->block, flags);
         ath5k_txbuf_free(sc, sc->bbuf);
         sc->bbuf->skb = skb;
         ret = ath5k_beacon_setup(sc, sc->bbuf);
         if (ret)
                 sc->bbuf->skb = NULL;
-        else {
+        spin_unlock_irqrestore(&sc->block, flags);
+        if (!ret) {
                 ath5k_beacon_config(sc);
                 mmiowb();
         }
diff --git a/drivers/net/wireless/ath5k/base.h b/drivers/net/wireless/ath5k/base.h
index d7e03e6b8271..7ec2f377d5c7 100644
--- a/drivers/net/wireless/ath5k/base.h
+++ b/drivers/net/wireless/ath5k/base.h
@@ -172,6 +172,7 @@ struct ath5k_softc {
         struct tasklet_struct   txtq;           /* tx intr tasklet */
         struct ath5k_led        tx_led;         /* tx led */
 
+        spinlock_t              block;          /* protects beacon */
         struct ath5k_buf        *bbuf;          /* beacon buffer */
         unsigned int            bhalq,          /* SW q for outgoing beacons */
                                 bmisscount,     /* missed beacon transmits */