mac80211: allow setting queue_len for drivers not using wake_tx_queue

Currently a mac80211 driver can only set the txq_limit when using
wake_tx_queue. Not all drivers use wake_tx_queue. This patch adds a new
element to wiphy allowing a driver to set a custom tx_queue_len and the
code that will apply it in case it is set. The current default is
1000 which is too low for ath11k when doing HE rates.

Signed-off-by: John Crispin <john@phrozen.org>
Link: https://lore.kernel.org/r/20200211122605.13002-1-john@phrozen.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/iface.c

@@ -1834,6 +1834,10 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 					if_setup, txqs, 1);
 		if (!ndev)
 			return -ENOMEM;
+
+		if (!local->ops->wake_tx_queue && local->hw.wiphy->tx_queue_len)
+			ndev->tx_queue_len = local->hw.wiphy->tx_queue_len;
+
 		dev_net_set(ndev, wiphy_net(local->hw.wiphy));
 
 		ndev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);