ath9k: handle low buffer space for virtual wiphys

ath9k virtual wiphys all share the same internal buffer space
for TX but they do not share the mac80211 skb queues. When
ath9k detects it is running low on buffer space to TX it tells
mac80211 to stop sending it skbs its way but it always does
this only for the primary wiphy. This means mac80211 won't know
its best to avoid sending ath9k more skbs on a separate virtual
wiphy. The same issue is present for reliving the skb queue.

Since ath9k does not keep track of which virtual wiphy is hammering
on TX silence all wiphy's TX when we're low on buffer space. When
we're free on buffer space only bother informing the virtual wiphy
which is active that we have free buffers.

Cc: Jouni.Malinen <Jouni.Malinen@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/virtual.c b/drivers/net/wireless/ath/ath9k/virtual.c
index 69a871ba051..0a36b572294 100644
--- a/drivers/net/wireless/ath/ath9k/virtual.c
+++ b/drivers/net/wireless/ath/ath9k/virtual.c
@@ -697,3 +697,55 @@ void ath9k_set_wiphy_idle(struct ath_wiphy *aphy, bool idle)
                   wiphy_name(aphy->hw->wiphy),
                   idle ? "idle" : "not-idle");
 }
+/* Only bother starting a queue on an active virtual wiphy */
+void ath_mac80211_start_queue(struct ath_softc *sc, u16 skb_queue)
+{
+        struct ieee80211_hw *hw = sc->pri_wiphy->hw;
+        unsigned int i;
+
+        spin_lock_bh(&sc->wiphy_lock);
+
+        /* Start the primary wiphy */
+        if (sc->pri_wiphy->state == ATH_WIPHY_ACTIVE) {
+                ieee80211_wake_queue(hw, skb_queue);
+                goto unlock;
+        }
+
+        /* Now start the secondary wiphy queues */
+        for (i = 0; i < sc->num_sec_wiphy; i++) {
+                struct ath_wiphy *aphy = sc->sec_wiphy[i];
+                if (!aphy)
+                        continue;
+                if (aphy->state != ATH_WIPHY_ACTIVE)
+                        continue;
+
+                hw = aphy->hw;
+                ieee80211_wake_queue(hw, skb_queue);
+                break;
+        }
+
+unlock:
+        spin_unlock_bh(&sc->wiphy_lock);
+}
+
+/* Go ahead and propagate information to all virtual wiphys, it won't hurt */
+void ath_mac80211_stop_queue(struct ath_softc *sc, u16 skb_queue)
+{
+        struct ieee80211_hw *hw = sc->pri_wiphy->hw;
+        unsigned int i;
+
+        spin_lock_bh(&sc->wiphy_lock);
+
+        /* Stop the primary wiphy */
+        ieee80211_stop_queue(hw, skb_queue);
+
+        /* Now stop the secondary wiphy queues */
+        for (i = 0; i < sc->num_sec_wiphy; i++) {
+                struct ath_wiphy *aphy = sc->sec_wiphy[i];
+                if (!aphy)
+                        continue;
+                hw = aphy->hw;
+                ieee80211_stop_queue(hw, skb_queue);
+        }
+        spin_unlock_bh(&sc->wiphy_lock);
+}