generic: drop extra-old-deprecated pending fix patch for sch codel

Patch 620-net_sched-codel-do-not-defer-queue-length-update.patch is
actually an ancient patch that somehow manage to be ported for 7 solid
years.

This comes from [1] where a fix patch was proposed. Nobody notice that
the proposed patch was actually rejected upstream in favor of [2]. And
the upstream fix patch is present in kernel from version 4.18.

This means that we were actually fixing for a non existant bug and maybe
introducing regression down the line.

Drop the patch for good as we already have a fix for it in flace for a
long time.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=109581
[2] https://github.com/torvalds/linux/commit/35b42da69e35536da603a50e40aa6c41b2f7b0f8

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

diff --git a/target/linux/generic/pending-6.6/620-net_sched-codel-do-not-defer-queue-length-update.patch b/target/linux/generic/pending-6.6/620-net_sched-codel-do-not-defer-queue-length-update.patch
deleted file mode 100644 (file)
index 4b4825a..0000000
--- a/target/linux/generic/pending-6.6/620-net_sched-codel-do-not-defer-queue-length-update.patch
+++ /dev/null
@@ -1,86 +0,0 @@
-From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
-Date: Mon, 21 Aug 2017 11:14:14 +0300
-Subject: [PATCH] net_sched/codel: do not defer queue length update
-
-When codel wants to drop last packet in ->dequeue() it cannot call
-qdisc_tree_reduce_backlog() right away - it will notify parent qdisc
-about zero qlen and HTB/HFSC will deactivate class. The same class will
-be deactivated second time by caller of ->dequeue(). Currently codel and
-fq_codel defer update. This triggers warning in HFSC when it's qlen != 0
-but there is no active classes.
-
-This patch update parent queue length immediately: just temporary increase
-qlen around qdisc_tree_reduce_backlog() to prevent first class deactivation
-if we have skb to return.
-
-This might open another problem in HFSC - now operation peek could fail and
-deactivate parent class.
-
-Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
-Link: https://bugzilla.kernel.org/show_bug.cgi?id=109581
----
-
---- a/net/sched/sch_codel.c
-+++ b/net/sched/sch_codel.c
-@@ -95,11 +95,17 @@ static struct sk_buff *codel_qdisc_deque
-                           &q->stats, qdisc_pkt_len, codel_get_enqueue_time,
-                           drop_func, dequeue_func);
- 
--      /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
--       * or HTB crashes. Defer it for next round.
-+      /* If our qlen is 0 qdisc_tree_reduce_backlog() will deactivate
-+       * parent class, dequeue in parent qdisc will do the same if we
-+       * return skb. Temporary increment qlen if we have skb.
-        */
--      if (q->stats.drop_count && sch->q.qlen) {
--              qdisc_tree_reduce_backlog(sch, q->stats.drop_count, q->stats.drop_len);
-+      if (q->stats.drop_count) {
-+              if (skb)
-+                      sch->q.qlen++;
-+              qdisc_tree_reduce_backlog(sch, q->stats.drop_count,
-+                                        q->stats.drop_len);
-+              if (skb)
-+                      sch->q.qlen--;
-               q->stats.drop_count = 0;
-               q->stats.drop_len = 0;
-       }
---- a/net/sched/sch_fq_codel.c
-+++ b/net/sched/sch_fq_codel.c
-@@ -304,6 +304,21 @@ begin:
-                           &flow->cvars, &q->cstats, qdisc_pkt_len,
-                           codel_get_enqueue_time, drop_func, dequeue_func);
- 
-+      /* If our qlen is 0 qdisc_tree_reduce_backlog() will deactivate
-+       * parent class, dequeue in parent qdisc will do the same if we
-+       * return skb. Temporary increment qlen if we have skb.
-+       */
-+      if (q->cstats.drop_count) {
-+              if (skb)
-+                      sch->q.qlen++;
-+              qdisc_tree_reduce_backlog(sch, q->cstats.drop_count,
-+                                        q->cstats.drop_len);
-+              if (skb)
-+                      sch->q.qlen--;
-+              q->cstats.drop_count = 0;
-+              q->cstats.drop_len = 0;
-+      }
-+
-       if (!skb) {
-               /* force a pass through old_flows to prevent starvation */
-               if ((head == &q->new_flows) && !list_empty(&q->old_flows))
-@@ -314,15 +329,6 @@ begin:
-       }
-       qdisc_bstats_update(sch, skb);
-       flow->deficit -= qdisc_pkt_len(skb);
--      /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
--       * or HTB crashes. Defer it for next round.
--       */
--      if (q->cstats.drop_count && sch->q.qlen) {
--              qdisc_tree_reduce_backlog(sch, q->cstats.drop_count,
--                                        q->cstats.drop_len);
--              q->cstats.drop_count = 0;
--              q->cstats.drop_len = 0;
--      }
-       return skb;
- }
-