[openwrt/openwrt] mac80211: merge a few pending tx related fixes
LEDE Commits
lede-commits at lists.infradead.org
Sun Mar 28 11:16:38 BST 2021
nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/571aedbc6cbb7a9bfc96bcad543a39d158925cbc
commit 571aedbc6cbb7a9bfc96bcad543a39d158925cbc
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Sun Mar 28 12:15:42 2021 +0200
mac80211: merge a few pending tx related fixes
Improve performance and fix potential mgmt tx hangs/warnings
Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
.../subsys/370-mac80211-fix-TXQ-AC-confusion.patch | 61 ++++++++++++++++++++++
...n-t-apply-flow-control-on-management-fram.patch | 60 +++++++++++++++++++++
...0211-set-sk_pacing_shift-for-802.3-txpath.patch | 21 ++++++++
3 files changed, 142 insertions(+)
diff --git a/package/kernel/mac80211/patches/subsys/370-mac80211-fix-TXQ-AC-confusion.patch b/package/kernel/mac80211/patches/subsys/370-mac80211-fix-TXQ-AC-confusion.patch
new file mode 100644
index 0000000000..0b7c8dd49b
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/370-mac80211-fix-TXQ-AC-confusion.patch
@@ -0,0 +1,61 @@
+From: Johannes Berg <johannes.berg at intel.com>
+Date: Tue, 23 Mar 2021 21:05:01 +0100
+Subject: [PATCH] mac80211: fix TXQ AC confusion
+
+Normally, TXQs have
+
+ txq->tid = tid;
+ txq->ac = ieee80211_ac_from_tid(tid);
+
+However, the special management TXQ actually has
+
+ txq->tid = IEEE80211_NUM_TIDS; // 16
+ txq->ac = IEEE80211_AC_VO;
+
+This makes sense, but ieee80211_ac_from_tid(16) is the same
+as ieee80211_ac_from_tid(0) which is just IEEE80211_AC_BE.
+
+Now, normally this is fine. However, if the netdev queues
+were stopped, then the code in ieee80211_tx_dequeue() will
+propagate the stop from the interface (vif->txqs_stopped[])
+if the AC 2 (ieee80211_ac_from_tid(txq->tid)) is marked as
+stopped. On wake, however, __ieee80211_wake_txqs() will wake
+the TXQ if AC 0 (txq->ac) is woken up.
+
+If a driver stops all queues with ieee80211_stop_tx_queues()
+and then wakes them again with ieee80211_wake_tx_queues(),
+the ieee80211_wake_txqs() tasklet will run to resync queue
+and TXQ state. If all queues were woken, then what'll happen
+is that _ieee80211_wake_txqs() will run in order of HW queues
+0-3, typically (and certainly for iwlwifi) corresponding to
+ACs 0-3, so it'll call __ieee80211_wake_txqs() for each AC in
+order 0-3.
+
+When __ieee80211_wake_txqs() is called for AC 0 (VO) that'll
+wake up the management TXQ (remember its tid is 16), and the
+driver's wake_tx_queue() will be called. That tries to get a
+frame, which will immediately *stop* the TXQ again, because
+now we check against AC 2, and AC 2 hasn't yet been marked as
+woken up again in sdata->vif.txqs_stopped[] since we're only
+in the __ieee80211_wake_txqs() call for AC 0.
+
+Thus, the management TXQ will never be started again.
+
+Fix this by checking txq->ac directly instead of calculating
+the AC as ieee80211_ac_from_tid(txq->tid).
+
+Fixes: adf8ed01e4fd ("mac80211: add an optional TXQ for other PS-buffered frames")
+Signed-off-by: Johannes Berg <johannes.berg at intel.com>
+---
+
+--- a/net/mac80211/tx.c
++++ b/net/mac80211/tx.c
+@@ -3589,7 +3589,7 @@ begin:
+ test_bit(IEEE80211_TXQ_STOP_NETIF_TX, &txqi->flags))
+ goto out;
+
+- if (vif->txqs_stopped[ieee80211_ac_from_tid(txq->tid)]) {
++ if (vif->txqs_stopped[txq->ac]) {
+ set_bit(IEEE80211_TXQ_STOP_NETIF_TX, &txqi->flags);
+ goto out;
+ }
diff --git a/package/kernel/mac80211/patches/subsys/371-mac80211-don-t-apply-flow-control-on-management-fram.patch b/package/kernel/mac80211/patches/subsys/371-mac80211-don-t-apply-flow-control-on-management-fram.patch
new file mode 100644
index 0000000000..b439a3814c
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/371-mac80211-don-t-apply-flow-control-on-management-fram.patch
@@ -0,0 +1,60 @@
+From: Johannes Berg <johannes.berg at intel.com>
+Date: Fri, 19 Mar 2021 23:28:01 +0100
+Subject: [PATCH] mac80211: don't apply flow control on management frames
+
+In some cases (depending on the driver, but it's true e.g. for
+iwlwifi) we're using an internal TXQ for management packets,
+mostly to simplify the code and to have a place to queue them.
+However, it appears that in certain cases we can confuse the
+code and management frames are dropped, which is certainly not
+what we want.
+
+Short-circuit the processing of management frames. To keep the
+impact minimal, only put them on the frags queue and check the
+tid == management only for doing that and to skip the airtime
+fairness checks, if applicable.
+
+Signed-off-by: Johannes Berg <johannes.berg at intel.com>
+---
+
+--- a/net/mac80211/tx.c
++++ b/net/mac80211/tx.c
+@@ -5,7 +5,7 @@
+ * Copyright 2006-2007 Jiri Benc <jbenc at suse.cz>
+ * Copyright 2007 Johannes Berg <johannes at sipsolutions.net>
+ * Copyright 2013-2014 Intel Mobile Communications GmbH
+- * Copyright (C) 2018-2020 Intel Corporation
++ * Copyright (C) 2018-2021 Intel Corporation
+ *
+ * Transmit and frame generation functions.
+ */
+@@ -1403,8 +1403,17 @@ static void ieee80211_txq_enqueue(struct
+ ieee80211_set_skb_enqueue_time(skb);
+
+ spin_lock_bh(&fq->lock);
+- fq_tin_enqueue(fq, tin, flow_idx, skb,
+- fq_skb_free_func);
++ /*
++ * For management frames, don't really apply codel etc.,
++ * we don't want to apply any shaping or anything we just
++ * want to simplify the driver API by having them on the
++ * txqi.
++ */
++ if (unlikely(txqi->txq.tid == IEEE80211_NUM_TIDS))
++ __skb_queue_tail(&txqi->frags, skb);
++ else
++ fq_tin_enqueue(fq, tin, flow_idx, skb,
++ fq_skb_free_func);
+ spin_unlock_bh(&fq->lock);
+ }
+
+@@ -3846,6 +3855,9 @@ bool ieee80211_txq_airtime_check(struct
+ if (!txq->sta)
+ return true;
+
++ if (unlikely(txq->tid == IEEE80211_NUM_TIDS))
++ return true;
++
+ sta = container_of(txq->sta, struct sta_info, sta);
+ if (atomic_read(&sta->airtime[txq->ac].aql_tx_pending) <
+ sta->airtime[txq->ac].aql_limit_low)
diff --git a/package/kernel/mac80211/patches/subsys/372-mac80211-set-sk_pacing_shift-for-802.3-txpath.patch b/package/kernel/mac80211/patches/subsys/372-mac80211-set-sk_pacing_shift-for-802.3-txpath.patch
new file mode 100644
index 0000000000..4d8a91a413
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/372-mac80211-set-sk_pacing_shift-for-802.3-txpath.patch
@@ -0,0 +1,21 @@
+From: Lorenzo Bianconi <lorenzo at kernel.org>
+Date: Mon, 8 Mar 2021 23:01:49 +0100
+Subject: [PATCH] mac80211: set sk_pacing_shift for 802.3 txpath
+
+Similar to 802.11 txpath, set socket sk_pacing_shift for 802.3 tx path.
+
+Signed-off-by: Lorenzo Bianconi <lorenzo at kernel.org>
+---
+
+--- a/net/mac80211/tx.c
++++ b/net/mac80211/tx.c
+@@ -4173,6 +4173,9 @@ static bool ieee80211_tx_8023(struct iee
+ unsigned long flags;
+ int q = info->hw_queue;
+
++ if (sta)
++ sk_pacing_shift_update(skb->sk, local->hw.tx_sk_pacing_shift);
++
+ if (ieee80211_queue_skb(local, sdata, sta, skb))
+ return true;
+
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