mac80211: introduce flush operation
We've long lacked a good confirmation that frames
have really gone out, e.g. before going off-channel
for a scan. Add a flush() operation that drivers
can implement to provide that confirmation, and use
it in a few places:
* before scanning sends the nullfunc frames
* after scanning sends the nullfunc frames, if any
* when going idle, to send any pending frames
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 718a5f1..4dee69a 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -896,6 +896,16 @@
return 0;
}
+static void mac80211_hwsim_flush(struct ieee80211_hw *hw, bool drop)
+{
+ /*
+ * In this special case, there's nothing we need to
+ * do because hwsim does transmission synchronously.
+ * In the future, when it does transmissions via
+ * userspace, we may need to do something.
+ */
+}
+
static const struct ieee80211_ops mac80211_hwsim_ops =
{
@@ -912,6 +922,7 @@
.conf_tx = mac80211_hwsim_conf_tx,
CFG80211_TESTMODE_CMD(mac80211_hwsim_testmode_cmd)
.ampdu_action = mac80211_hwsim_ampdu_action,
+ .flush = mac80211_hwsim_flush,
};
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 494ac69..77ea34b 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1545,6 +1545,10 @@
* and need to call wiphy_rfkill_set_hw_state() in the callback.
*
* @testmode_cmd: Implement a cfg80211 test mode command.
+ *
+ * @flush: Flush all pending frames from the hardware queue, making sure
+ * that the hardware queues are empty. If the parameter @drop is set
+ * to %true, pending frames may be dropped.
*/
struct ieee80211_ops {
int (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);
@@ -1601,6 +1605,7 @@
#ifdef CONFIG_NL80211_TESTMODE
int (*testmode_cmd)(struct ieee80211_hw *hw, void *data, int len);
#endif
+ void (*flush)(struct ieee80211_hw *hw, bool drop);
};
/**
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 727e4cf..cbe133b 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -259,4 +259,11 @@
if (local->ops->rfkill_poll)
local->ops->rfkill_poll(&local->hw);
}
+
+static inline void drv_flush(struct ieee80211_local *local, bool drop)
+{
+ trace_drv_flush(local, drop);
+ if (local->ops->flush)
+ local->ops->flush(&local->hw, drop);
+}
#endif /* __MAC80211_DRIVER_OPS */
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 7a849b9..977cc75 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -690,6 +690,27 @@
LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG, __entry->action, __entry->tid, __entry->ret
)
);
+
+TRACE_EVENT(drv_flush,
+ TP_PROTO(struct ieee80211_local *local, bool drop),
+
+ TP_ARGS(local, drop),
+
+ TP_STRUCT__entry(
+ LOCAL_ENTRY
+ __field(bool, drop)
+ ),
+
+ TP_fast_assign(
+ LOCAL_ASSIGN;
+ __entry->drop = drop;
+ ),
+
+ TP_printk(
+ LOCAL_PR_FMT " drop:%d",
+ LOCAL_PR_ARG, __entry->drop
+ )
+);
#endif /* !__MAC80211_DRIVER_TRACE || TRACE_HEADER_MULTI_READ */
#undef TRACE_INCLUDE_PATH
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1ceca14..389dc8d 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -917,6 +917,8 @@
wiphy_name(local->hw.wiphy));
#endif
+ drv_flush(local, false);
+
local->hw.conf.flags |= IEEE80211_CONF_IDLE;
return IEEE80211_CONF_CHANGE_IDLE;
}
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index ae18300..d98c45e 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -418,9 +418,10 @@
local->next_scan_state = SCAN_DECISION;
local->scan_channel_idx = 0;
+ drv_flush(local, false);
+
ieee80211_configure_filter(local);
- /* TODO: start scan as soon as all nullfunc frames are ACKed */
ieee80211_queue_delayed_work(&local->hw,
&local->scan_work,
IEEE80211_CHANNEL_TIME);
@@ -584,8 +585,16 @@
__set_bit(SCAN_OFF_CHANNEL, &local->scanning);
+ /*
+ * What if the nullfunc frames didn't arrive?
+ */
+ drv_flush(local, false);
+ if (local->ops->flush)
+ *next_delay = 0;
+ else
+ *next_delay = HZ / 10;
+
/* advance to the next channel to be scanned */
- *next_delay = HZ / 10;
local->next_scan_state = SCAN_SET_CHANNEL;
}