mirror of
				git://git.openwrt.org/openwrt/openwrt.git
				synced 2025-11-04 06:54:27 -05:00 
			
		
		
		
	Without this patch we have to manually bring up the CPU interface in failsafe mode. This was backported from kernel 5.12. Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> Tested-by: Rafał Miłecki <rafal@milecki.pl>
		
			
				
	
	
		
			86 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			86 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From 9d5ef190e5615a7b63af89f88c4106a5bc127974 Mon Sep 17 00:00:00 2001
 | 
						|
From: Vladimir Oltean <vladimir.oltean@nxp.com>
 | 
						|
Date: Fri, 5 Feb 2021 15:37:10 +0200
 | 
						|
Subject: [PATCH] net: dsa: automatically bring up DSA master when opening user
 | 
						|
 port
 | 
						|
 | 
						|
DSA wants the master interface to be open before the user port is due to
 | 
						|
historical reasons. The promiscuity of interfaces that are down used to
 | 
						|
have issues, as referenced Lennert Buytenhek in commit df02c6ff2e39
 | 
						|
("dsa: fix master interface allmulti/promisc handling").
 | 
						|
 | 
						|
The bugfix mentioned there, commit b6c40d68ff64 ("net: only invoke
 | 
						|
dev->change_rx_flags when device is UP"), was basically a "don't do
 | 
						|
that" approach to working around the promiscuity while down issue.
 | 
						|
 | 
						|
Further work done by Vlad Yasevich in commit d2615bf45069 ("net: core:
 | 
						|
Always propagate flag changes to interfaces") has resolved the
 | 
						|
underlying issue, and it is strictly up to the DSA and 8021q drivers
 | 
						|
now, it is no longer mandated by the networking core that the master
 | 
						|
interface must be up when changing its promiscuity.
 | 
						|
 | 
						|
From DSA's point of view, deciding to error out in dsa_slave_open
 | 
						|
because the master isn't up is
 | 
						|
(a) a bad user experience and
 | 
						|
(b) knocking at an open door.
 | 
						|
Even if there still was an issue with promiscuity while down, DSA could
 | 
						|
still just open the master and avoid it.
 | 
						|
 | 
						|
Doing it this way has the additional benefit that user space can now
 | 
						|
remove DSA-specific workarounds, like systemd-networkd with BindCarrier:
 | 
						|
https://github.com/systemd/systemd/issues/7478
 | 
						|
 | 
						|
And we can finally remove one of the 2 bullets in the "Common pitfalls
 | 
						|
using DSA setups" chapter.
 | 
						|
 | 
						|
Tested with two cascaded DSA switches:
 | 
						|
 | 
						|
$ ip link set sw0p2 up
 | 
						|
fsl_enetc 0000:00:00.2 eno2: configuring for fixed/internal link mode
 | 
						|
fsl_enetc 0000:00:00.2 eno2: Link is Up - 1Gbps/Full - flow control rx/tx
 | 
						|
mscc_felix 0000:00:00.5 swp0: configuring for fixed/sgmii link mode
 | 
						|
mscc_felix 0000:00:00.5 swp0: Link is Up - 1Gbps/Full - flow control off
 | 
						|
8021q: adding VLAN 0 to HW filter on device swp0
 | 
						|
sja1105 spi2.0 sw0p2: configuring for phy/rgmii-id link mode
 | 
						|
IPv6: ADDRCONF(NETDEV_CHANGE): eno2: link becomes ready
 | 
						|
IPv6: ADDRCONF(NETDEV_CHANGE): swp0: link becomes ready
 | 
						|
 | 
						|
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
 | 
						|
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
 | 
						|
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
 | 
						|
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 | 
						|
---
 | 
						|
 Documentation/networking/dsa/dsa.rst | 4 ----
 | 
						|
 net/dsa/slave.c                      | 7 +++++--
 | 
						|
 2 files changed, 5 insertions(+), 6 deletions(-)
 | 
						|
 | 
						|
--- a/Documentation/networking/dsa/dsa.rst
 | 
						|
+++ b/Documentation/networking/dsa/dsa.rst
 | 
						|
@@ -273,10 +273,6 @@ will not make us go through the switch t
 | 
						|
 the Ethernet switch on the other end, expecting a tag will typically drop this
 | 
						|
 frame.
 | 
						|
 
 | 
						|
-Slave network devices check that the master network device is UP before allowing
 | 
						|
-you to administratively bring UP these slave network devices. A common
 | 
						|
-configuration mistake is forgetting to bring UP the master network device first.
 | 
						|
-
 | 
						|
 Interactions with other subsystems
 | 
						|
 ==================================
 | 
						|
 
 | 
						|
--- a/net/dsa/slave.c
 | 
						|
+++ b/net/dsa/slave.c
 | 
						|
@@ -70,8 +70,11 @@ static int dsa_slave_open(struct net_dev
 | 
						|
 	struct dsa_port *dp = dsa_slave_to_port(dev);
 | 
						|
 	int err;
 | 
						|
 
 | 
						|
-	if (!(master->flags & IFF_UP))
 | 
						|
-		return -ENETDOWN;
 | 
						|
+	err = dev_open(master, NULL);
 | 
						|
+	if (err < 0) {
 | 
						|
+		netdev_err(dev, "failed to open master %s\n", master->name);
 | 
						|
+		goto out;
 | 
						|
+	}
 | 
						|
 
 | 
						|
 	if (!ether_addr_equal(dev->dev_addr, master->dev_addr)) {
 | 
						|
 		err = dev_uc_add(master, dev->dev_addr);
 |