ath9k: Add workaround to recover from failed channel changes
It looks like channel change may fail in some cases and end up leaving
the hardware in state where it cannot transmit any frames. Add a
workaround to recover from this state if we detect that wiphy
selection is failing due to wiphys not leaving PAUSING state.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/virtual.c b/drivers/net/wireless/ath9k/virtual.c
index 6122f48..913d204 100644
--- a/drivers/net/wireless/ath9k/virtual.c
+++ b/drivers/net/wireless/ath9k/virtual.c
@@ -432,6 +432,18 @@
return ret;
}
+static void __ath9k_wiphy_mark_all_paused(struct ath_softc *sc)
+{
+ int i;
+ if (sc->pri_wiphy->state != ATH_WIPHY_INACTIVE)
+ sc->pri_wiphy->state = ATH_WIPHY_PAUSED;
+ for (i = 0; i < sc->num_sec_wiphy; i++) {
+ if (sc->sec_wiphy[i] &&
+ sc->sec_wiphy[i]->state != ATH_WIPHY_INACTIVE)
+ sc->sec_wiphy[i]->state = ATH_WIPHY_PAUSED;
+ }
+}
+
/* caller must hold wiphy_lock */
static void __ath9k_wiphy_pause_all(struct ath_softc *sc)
{
@@ -452,9 +464,34 @@
spin_lock_bh(&sc->wiphy_lock);
if (__ath9k_wiphy_pausing(sc)) {
+ if (sc->wiphy_select_failures == 0)
+ sc->wiphy_select_first_fail = jiffies;
+ sc->wiphy_select_failures++;
+ if (time_after(jiffies, sc->wiphy_select_first_fail + HZ / 2))
+ {
+ printk(KERN_DEBUG "ath9k: Previous wiphy select timed "
+ "out; disable/enable hw to recover\n");
+ __ath9k_wiphy_mark_all_paused(sc);
+ /*
+ * TODO: this workaround to fix hardware is unlikely to
+ * be specific to virtual wiphy changes. It can happen
+ * on normal channel change, too, and as such, this
+ * should really be made more generic. For example,
+ * tricker radio disable/enable on GTT interrupt burst
+ * (say, 10 GTT interrupts received without any TX
+ * frame being completed)
+ */
+ spin_unlock_bh(&sc->wiphy_lock);
+ ath_radio_disable(sc);
+ ath_radio_enable(sc);
+ queue_work(aphy->sc->hw->workqueue,
+ &aphy->sc->chan_work);
+ return -EBUSY; /* previous select still in progress */
+ }
spin_unlock_bh(&sc->wiphy_lock);
return -EBUSY; /* previous select still in progress */
}
+ sc->wiphy_select_failures = 0;
/* Store the new channel */
sc->chan_idx = aphy->chan_idx;