iwlwifi: add mac80211 flush callback support

Adding flush callback support in the driver. Two type of flush can be
issued by mac80211:
1. drop = true: frame drop is ok, issue REPLY_TXFIFO_FLUSH host command
to uCode to drop all the frames in tx fifo queues; then return the
control back to mac80211
2. drop = false: wait for either all the frames in tx fifo queues been
transmitted, or timeout; then return the control back to mac80211

If the flush request coming from mac80211, mac80211 will make sure there
are no additional frames push down to driver before flush operation is
completed.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 22c0149e5d4a..c735a39ec176 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -3639,6 +3639,44 @@ out_exit:
 	IWL_DEBUG_MAC80211(priv, "leave\n");
 }
 
+static void iwl_mac_flush(struct ieee80211_hw *hw, bool drop)
+{
+	struct iwl_priv *priv = hw->priv;
+
+	mutex_lock(&priv->mutex);
+	IWL_DEBUG_MAC80211(priv, "enter\n");
+
+	/* do not support "flush" */
+	if (!priv->cfg->ops->lib->txfifo_flush)
+		goto done;
+
+	if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
+		IWL_DEBUG_TX(priv, "Aborting flush due to device shutdown\n");
+		goto done;
+	}
+	if (iwl_is_rfkill(priv)) {
+		IWL_DEBUG_TX(priv, "Aborting flush due to RF Kill\n");
+		goto done;
+	}
+
+	/*
+	 * mac80211 will not push any more frames for transmit
+	 * until the flush is completed
+	 */
+	if (drop) {
+		IWL_DEBUG_MAC80211(priv, "send flush command\n");
+		if (priv->cfg->ops->lib->txfifo_flush(priv, IWL_DROP_ALL)) {
+			IWL_ERR(priv, "flush request fail\n");
+			goto done;
+		}
+	}
+	IWL_DEBUG_MAC80211(priv, "wait transmit/flush all frames\n");
+	iwlagn_wait_tx_queue_empty(priv);
+done:
+	mutex_unlock(&priv->mutex);
+	IWL_DEBUG_MAC80211(priv, "leave\n");
+}
+
 /*****************************************************************************
  *
  * driver setup and teardown
@@ -3812,6 +3850,7 @@ static struct ieee80211_ops iwl_hw_ops = {
 	.sta_add = iwlagn_mac_sta_add,
 	.sta_remove = iwl_mac_sta_remove,
 	.channel_switch = iwl_mac_channel_switch,
+	.flush = iwl_mac_flush,
 };
 
 static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)