netdev - [PATCH net-next] net: dsa: mv88e6xxx: don't set non-existing learn2all bit for 6220/6250

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Message-Id: <20201208090109.363-1-rasmus.villemoes@prevas.dk>
Date:   Tue,  8 Dec 2020 10:01:09 +0100
From:   Rasmus Villemoes <rasmus.villemoes@...vas.dk>
To:     netdev@...r.kernel.org
Cc:     Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...il.com>,
        Jakub Kicinski <kuba@...nel.org>,
        "David S. Miller" <davem@...emloft.net>,
        Vladimir Oltean <olteanv@...il.com>,
        Hubert Feurstein <h.feurstein@...il.com>,
        Rasmus Villemoes <rasmus.villemoes@...vas.dk>
Subject: [PATCH net-next] net: dsa: mv88e6xxx: don't set non-existing learn2all bit for 6220/6250

The 6220 and 6250 switches do not have a learn2all bit in global1, ATU
control register; bit 3 is reserved.

On the switches that do have that bit, it is used to control whether
learning frames are sent out the ports that have the message_port bit
set. So rather than adding yet another chip method, use the existence
of the ->port_setup_message_port method as a proxy for determining
whether the learn2all bit exists (and should be set).

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@...vas.dk>
---

This doesn't fix anything from what I can tell, in particular not the
VLAN problems I'm having, so just tagging for net-next. But I do think
it's worth it on the general principle of not poking around in
undocumented/reserved bits.

 drivers/net/dsa/mv88e6xxx/chip.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 25449f634889..0245f3dfc1cd 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -1347,9 +1347,11 @@ static int mv88e6xxx_atu_setup(struct mv88e6xxx_chip *chip)
 	if (err)
 		return err;

-	err = mv88e6xxx_g1_atu_set_learn2all(chip, true);
-	if (err)
-		return err;
+	if (chip->info->ops->port_setup_message_port) {
+		err = mv88e6xxx_g1_atu_set_learn2all(chip, true);
+		if (err)
+			return err;
+	}

 	return mv88e6xxx_g1_atu_set_age_time(chip, 300000);
 }
-- 
2.23.0