Ath5k: flush work

Make sure that the irq is not in progress after stop. This means
two things:
- ensure the intr setting register is set by flushing posted values
- call synchronize_irq() after that

Also flush stop tx write, inform callers of the tx stop about still
pending transfers (unsuccessful stop) and finally don't wait another
3ms in ath5k_rx_stop, since ath5k_hw_stop_rx_dma ensures transfer to
be finished.

Make sure all writes will be ordered in respect to locks by mmiowb().

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

2 files changed, 15 insertions, 2 deletions

diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c
index c5bf8a2ef5cd..8e9afb3b3a56 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -43,7 +43,9 @@
 #include <linux/version.h>
 #include <linux/module.h>
 #include <linux/delay.h>
+#include <linux/hardirq.h>
 #include <linux/if.h>
+#include <linux/io.h>
 #include <linux/netdevice.h>
 #include <linux/cache.h>
 #include <linux/pci.h>
@@ -1249,6 +1251,7 @@ ath5k_txbuf_setup(struct ath5k_softc *sc, struct ath5k_buf *bf)
 
         txq->link = &ds->ds_link;
         ath5k_hw_tx_start(ah, txq->qnum);
+        mmiowb();
         spin_unlock_bh(&txq->lock);
 
         return 0;
@@ -1583,7 +1586,6 @@ ath5k_rx_stop(struct ath5k_softc *sc)
         ath5k_hw_stop_pcu_recv(ah);     /* disable PCU */
         ath5k_hw_set_rx_filter(ah, 0);  /* clear recv filter */
         ath5k_hw_stop_rx_dma(ah);       /* disable DMA engine */
-        mdelay(3);                      /* 3ms is long enough for 1 frame */
 
         ath5k_debug_printrxbuffs(sc, ah);
 
@@ -2258,6 +2260,7 @@ ath5k_init(struct ath5k_softc *sc)
 
         ret = 0;
 done:
+        mmiowb();
         mutex_unlock(&sc->lock);
         return ret;
 }
@@ -2290,6 +2293,7 @@ ath5k_stop_locked(struct ath5k_softc *sc)
         if (!test_bit(ATH_STAT_INVALID, sc->status)) {
                 ath5k_led_off(sc);
                 ath5k_hw_set_intr(ah, 0);
+                synchronize_irq(sc->pdev->irq);
         }
         ath5k_txq_cleanup(sc);
         if (!test_bit(ATH_STAT_INVALID, sc->status)) {
@@ -2339,6 +2343,7 @@ ath5k_stop_hw(struct ath5k_softc *sc)
                 }
         }
         ath5k_txbuf_free(sc, sc->bbuf);
+        mmiowb();
         mutex_unlock(&sc->lock);
 
         del_timer_sync(&sc->calib_tim);
@@ -2804,6 +2809,7 @@ ath5k_config_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
                 /* XXX: assoc id is set to 0 for now, mac80211 doesn't have
                  * a clean way of letting us retrieve this yet. */
                 ath5k_hw_set_associd(ah, ah->ah_bssid, 0);
+                mmiowb();
         }
 
         if (conf->changed & IEEE80211_IFCC_BEACON &&
@@ -2992,6 +2998,7 @@ ath5k_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
         }
 
 unlock:
+        mmiowb();
         mutex_unlock(&sc->lock);
         return ret;
 }
@@ -3065,8 +3072,10 @@ ath5k_beacon_update(struct ieee80211_hw *hw, struct sk_buff *skb)
         ret = ath5k_beacon_setup(sc, sc->bbuf);
         if (ret)
                 sc->bbuf->skb = NULL;
-        else
+        else {
                 ath5k_beacon_config(sc);
+                mmiowb();
+        }
 
 end:
         mutex_unlock(&sc->lock);
diff --git a/drivers/net/wireless/ath5k/hw.c b/drivers/net/wireless/ath5k/hw.c
index c6d12c53bda4..7ca87a557312 100644
--- a/drivers/net/wireless/ath5k/hw.c
+++ b/drivers/net/wireless/ath5k/hw.c
@@ -1440,6 +1440,7 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
 
                 /* Stop queue */
                 ath5k_hw_reg_write(ah, tx_queue, AR5K_CR);
+                ath5k_hw_reg_read(ah, AR5K_CR);
         } else {
                 /*
                  * Schedule TX disable and wait until queue is empty
@@ -1456,6 +1457,8 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
 
                 /* Clear register */
                 ath5k_hw_reg_write(ah, 0, AR5K_QCU_TXD);
+                if (pending)
+                        return -EBUSY;
         }
 
         /* TODO: Check for success else return error */
@@ -1716,6 +1719,7 @@ enum ath5k_int ath5k_hw_set_intr(struct ath5k_hw *ah, enum ath5k_int new_mask)
 
         /* ..re-enable interrupts */
         ath5k_hw_reg_write(ah, AR5K_IER_ENABLE, AR5K_IER);
+        ath5k_hw_reg_read(ah, AR5K_IER);
 
         return old_mask;
 }