ath9k: Add a simple virtual wiphy scheduler

This is a very simple scheduler that goes through the wiphys and
schedules one at a time every N milliseconds (current default value:
500 ms). This is enough for initial testing, but there are number of
areas where a more complex scheduler can improve operations greatly.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath9k/virtual.c b/drivers/net/wireless/ath9k/virtual.c
index 2b545319408d..1ff429b027d7 100644
--- a/drivers/net/wireless/ath9k/virtual.c
+++ b/drivers/net/wireless/ath9k/virtual.c
@@ -154,6 +154,11 @@ int ath9k_wiphy_add(struct ath_softc *sc)
 
         error = ieee80211_register_hw(hw);
 
+        if (error == 0) {
+                /* Make sure wiphy scheduler is started (if enabled) */
+                ath9k_wiphy_set_scheduler(sc, sc->wiphy_scheduler_int);
+        }
+
         return error;
 }
 
@@ -596,3 +601,62 @@ void ath9k_wiphy_pause_all_forced(struct ath_softc *sc,
         }
         spin_unlock_bh(&sc->wiphy_lock);
 }
+
+void ath9k_wiphy_work(struct work_struct *work)
+{
+        struct ath_softc *sc = container_of(work, struct ath_softc,
+                                            wiphy_work.work);
+        struct ath_wiphy *aphy = NULL;
+        bool first = true;
+
+        spin_lock_bh(&sc->wiphy_lock);
+
+        if (sc->wiphy_scheduler_int == 0) {
+                /* wiphy scheduler is disabled */
+                spin_unlock_bh(&sc->wiphy_lock);
+                return;
+        }
+
+try_again:
+        sc->wiphy_scheduler_index++;
+        while (sc->wiphy_scheduler_index <= sc->num_sec_wiphy) {
+                aphy = sc->sec_wiphy[sc->wiphy_scheduler_index - 1];
+                if (aphy && aphy->state != ATH_WIPHY_INACTIVE)
+                        break;
+
+                sc->wiphy_scheduler_index++;
+                aphy = NULL;
+        }
+        if (aphy == NULL) {
+                sc->wiphy_scheduler_index = 0;
+                if (sc->pri_wiphy->state == ATH_WIPHY_INACTIVE) {
+                        if (first) {
+                                first = false;
+                                goto try_again;
+                        }
+                        /* No wiphy is ready to be scheduled */
+                } else
+                        aphy = sc->pri_wiphy;
+        }
+
+        spin_unlock_bh(&sc->wiphy_lock);
+
+        if (aphy &&
+            aphy->state != ATH_WIPHY_ACTIVE && aphy->state != ATH_WIPHY_SCAN &&
+            ath9k_wiphy_select(aphy)) {
+                printk(KERN_DEBUG "ath9k: Failed to schedule virtual wiphy "
+                       "change\n");
+        }
+
+        queue_delayed_work(sc->hw->workqueue, &sc->wiphy_work,
+                           sc->wiphy_scheduler_int);
+}
+
+void ath9k_wiphy_set_scheduler(struct ath_softc *sc, unsigned int msec_int)
+{
+        cancel_delayed_work_sync(&sc->wiphy_work);
+        sc->wiphy_scheduler_int = msecs_to_jiffies(msec_int);
+        if (sc->wiphy_scheduler_int)
+                queue_delayed_work(sc->hw->workqueue, &sc->wiphy_work,
+                                   sc->wiphy_scheduler_int);
+}