Re: [PATCH v2 net-next] net/core: ensure features get disabled on new lower devs

From: Laura Abbott
Date: Fri Nov 13 2015 - 17:31:55 EST

On 11/13/2015 02:51 AM, Nikolay Aleksandrov wrote:
On 11/13/2015 11:29 AM, Jiri Pirko wrote:
Fri, Nov 13, 2015 at 01:26:18AM CET, f.fainelli@xxxxxxxxx wrote:
On 04/11/15 18:56, David Miller wrote:
Fixes: fd867d51f889 ("net/core: generic support for disabling netdev features down stack")
Reported-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jarod Wilson <jarod@xxxxxxxxxx>
v2: Based on suggestions from Alex, and with not changing err to ret, this
patch actually becomes quite minimal and doesn't ugly up the code much.

Applied, thanks.

This causes some warnings to be displayed for DSA stacked devices:

[ 1.272297] brcm-sf2 f0b00000.ethernet_switch: Starfighter 2 top:
4.00, core: 2.00 base: 0xf0c80000, IRQs: 68, 69
[ 1.283181] libphy: dsa slave smi: probed
[ 1.344088] f0b403c0.mdio:05: Broadcom BCM7445 PHY revision: 0xd0,
patch: 3
[ 1.658917] brcm-sf2 f0b00000.ethernet_switch gphy (uninitialized):
attached PHY at address 5 [Broadcom BCM7445]
[ 1.669414] brcm-sf2 f0b00000.ethernet_switch gphy: set_features()
failed (-1); wanted 0x0000000000004020, left 0x0000000000004820
[ 1.734202] brcm-sf2 f0b00000.ethernet_switch rgmii_1
(uninitialized): attached PHY at address 0 [Generic PHY]
[ 1.744486] brcm-sf2 f0b00000.ethernet_switch rgmii_1: set_features()
failed (-1); wanted 0x0000000000004020, left 0x0000000000004820
[ 1.809091] brcm-sf2 f0b00000.ethernet_switch rgmii_2
(uninitialized): attached PHY at address 1 [Generic PHY]
[ 1.819364] brcm-sf2 f0b00000.ethernet_switch rgmii_2: set_features()
failed (-1); wanted 0x0000000000004020, left 0x0000000000004820
[ 1.884090] brcm-sf2 f0b00000.ethernet_switch moca (uninitialized):
attached PHY at address 2 [Generic PHY]
[ 1.894109] brcm-sf2 f0b00000.ethernet_switch moca: set_features()
failed (-1); wanted 0x0000000000004020, left 0x0000000000004820

DSA slave network devices are not associated with their master network
device using the typical lower/upper netdev helpers.

I do not have a good fix to come up with yet, but if you see something
obvious with net/dsa/slave.c, feel free to send patches for testing, I
can boot net-next on this platform.

I'm having similar issues with bridge, with linus's git now:


Hmm, I think it's because the bridge and dsa/slave don't have ndo_set_features()
so err is left as -1 and thus an error is reported which isn't actually true.
Before in this case the features would just get set, so could you please try
the following patch ?

diff --git a/net/core/dev.c b/net/core/dev.c
index ab9b8d0d115e..4a1d198dbbff 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6426,6 +6426,8 @@ int __netdev_update_features(struct net_device *dev)

if (dev->netdev_ops->ndo_set_features)
err = dev->netdev_ops->ndo_set_features(dev, features);
+ else
+ err = 0;

if (unlikely(err < 0)) {

The patch seems to be working for at least one person who reported the
problem in Fedora rawhide


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