Netdev Archive on lore.kernel.org
help / color / mirror / Atom feed
From: DENG Qingfang <dqfext@gmail.com>
To: Sean Wang <sean.wang@mediatek.com>,
	Landen Chao <Landen.Chao@mediatek.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: "Eric Woudstra" <ericwouds@gmail.com>,
	"René van Dorst" <opensource@vdorst.com>,
	"Frank Wunderlich" <frank-w@public-files.de>
Subject: [RFC net-next v2 1/4] net: dsa: mt7530: enable assisted learning on CPU port
Date: Sun,  1 Aug 2021 03:10:19 +0800	[thread overview]
Message-ID: <20210731191023.1329446-2-dqfext@gmail.com> (raw)
In-Reply-To: <20210731191023.1329446-1-dqfext@gmail.com>

Consider the following bridge configuration, where bond0 is not
offloaded:

         +-- br0 --+
        / /   |     \
       / /    |      \
      /  |    |     bond0
     /   |    |     /   \
   swp0 swp1 swp2 swp3 swp4
     .        .       .
     .        .       .
     A        B       C

Address learning is enabled on offloaded ports (swp0~2) and the CPU
port, so when client A sends a packet to C, the following will happen:

1. The switch learns that client A can be reached at swp0.
2. The switch probably already knows that client C can be reached at the
   CPU port, so it forwards the packet to the CPU.
3. The bridge core knows client C can be reached at bond0, so it
   forwards the packet back to the switch.
4. The switch learns that client A can be reached at the CPU port.
5. The switch forwards the packet to either swp3 or swp4, according to
   the packet's tag.

That makes client A's MAC address flap between swp0 and the CPU port. If
client B sends a packet to A, it is possible that the packet is
forwarded to the CPU. With offload_fwd_mark = 1, the bridge core won't
forward it back to the switch, resulting in packet loss.

As we have the assisted_learning_on_cpu_port in DSA core now, enable
that and disable hardware learning on the CPU port.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
---
 drivers/net/dsa/mt7530.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 69f21b71614c..7e7e0a35e351 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2054,6 +2054,7 @@ mt7530_setup(struct dsa_switch *ds)
 	 * as two netdev instances.
 	 */
 	dn = dsa_to_port(ds, MT7530_CPU_PORT)->master->dev.of_node->parent;
+	ds->assisted_learning_on_cpu_port = true;
 	ds->mtu_enforcement_ingress = true;
 
 	if (priv->id == ID_MT7530) {
@@ -2124,15 +2125,15 @@ mt7530_setup(struct dsa_switch *ds)
 		mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
 			   PCR_MATRIX_CLR);
 
+		/* Disable learning by default on all ports */
+		mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
+
 		if (dsa_is_cpu_port(ds, i)) {
 			ret = mt753x_cpu_port_enable(ds, i);
 			if (ret)
 				return ret;
 		} else {
 			mt7530_port_disable(ds, i);
-
-			/* Disable learning by default on all user ports */
-			mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
 		}
 		/* Enable consistent egress tag */
 		mt7530_rmw(priv, MT7530_PVC_P(i), PVC_EG_TAG_MASK,
@@ -2289,6 +2290,9 @@ mt7531_setup(struct dsa_switch *ds)
 		mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
 			   PCR_MATRIX_CLR);
 
+		/* Disable learning by default on all ports */
+		mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
+
 		mt7530_set(priv, MT7531_DBG_CNT(i), MT7531_DIS_CLR);
 
 		if (dsa_is_cpu_port(ds, i)) {
@@ -2297,9 +2301,6 @@ mt7531_setup(struct dsa_switch *ds)
 				return ret;
 		} else {
 			mt7530_port_disable(ds, i);
-
-			/* Disable learning by default on all user ports */
-			mt7530_set(priv, MT7530_PSC_P(i), SA_DIS);
 		}
 
 		/* Enable consistent egress tag */
@@ -2307,6 +2308,7 @@ mt7531_setup(struct dsa_switch *ds)
 			   PVC_EG_TAG(MT7530_VLAN_EG_CONSISTENT));
 	}
 
+	ds->assisted_learning_on_cpu_port = true;
 	ds->mtu_enforcement_ingress = true;
 
 	/* Flush the FDB table */
-- 
2.25.1


  reply	other threads:[~2021-07-31 19:10 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-31 19:10 [RFC net-next v2 0/4] mt7530 software fallback bridging fix DENG Qingfang
2021-07-31 19:10 ` DENG Qingfang [this message]
2021-08-02 13:07   ` [RFC net-next v2 1/4] net: dsa: mt7530: enable assisted learning on CPU port Vladimir Oltean
2021-07-31 19:10 ` [RFC net-next v2 2/4] net: dsa: mt7530: use independent VLAN learning on VLAN-unaware bridges DENG Qingfang
2021-08-02 13:36   ` Vladimir Oltean
2021-07-31 19:10 ` [RFC net-next v2 3/4] net: dsa: mt7530: set STP state also on filter ID 1 DENG Qingfang
2021-08-02 13:43   ` Vladimir Oltean
2021-08-02 15:31     ` DENG Qingfang
2021-08-02 15:42       ` Vladimir Oltean
2021-08-02 15:58         ` DENG Qingfang
2021-08-02 21:00           ` Vladimir Oltean
2021-08-03  8:23             ` DENG Qingfang
2021-08-03  8:48               ` Vladimir Oltean
2021-07-31 19:10 ` [RFC net-next v2 4/4] Revert "mt7530 mt7530_fdb_write only set ivl bit vid larger than 1" DENG Qingfang
2021-08-02 13:44   ` Vladimir Oltean
2021-08-02 15:48     ` DENG Qingfang
2021-08-02 20:59       ` Vladimir Oltean

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210731191023.1329446-2-dqfext@gmail.com \
    --to=dqfext@gmail.com \
    --cc=Landen.Chao@mediatek.com \
    --cc=andrew@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=ericwouds@gmail.com \
    --cc=f.fainelli@gmail.com \
    --cc=frank-w@public-files.de \
    --cc=kuba@kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mediatek@lists.infradead.org \
    --cc=matthias.bgg@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=olteanv@gmail.com \
    --cc=opensource@vdorst.com \
    --cc=sean.wang@mediatek.com \
    --cc=vivien.didelot@gmail.com \
    --subject='Re: [RFC net-next v2 1/4] net: dsa: mt7530: enable assisted learning on CPU port' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).