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

From: Florian Fainelli <f.fainelli@gmail.com>
To: David Miller <davem@davemloft.net>, jarod@redhat.com
Cc: linux-kernel@vger.kernel.org, edumazet@google.com,
	j.vosburgh@gmail.com, vfalico@gmail.com,
	gospo@cumulusnetworks.com, jiri@resnulli.us, razor@blackwall.org,
	mkubecek@suse.cz, alexander.duyck@gmail.com,
	netdev@vger.kernel.org, Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Subject: Re: [PATCH v2 net-next] net/core: ensure features get disabled on new lower devs
Date: Thu, 12 Nov 2015 16:26:18 -0800	[thread overview]
Message-ID: <56452E2A.9050501@gmail.com> (raw)
In-Reply-To: <20151104.215632.964832400121049446.davem@davemloft.net>

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@cumulusnetworks.com>
>> Signed-off-by: Jarod Wilson <jarod@redhat.com>
>> ---
>> 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.
-- 
Florian