Re: [PATCH net-next 1/2] tg3: Fix NETIF_F_LOOPBACK error

[Mahesh Bandewar <maheshb@google.com>]

On Thu, May 19, 2011 at 11:57 PM, Michał Mirosław <mirqus@gmail.com> wrote:
> 2011/5/20 Matt Carlson <mcarlson@broadcom.com>:
>> On Thu, May 19, 2011 at 06:15:18PM -0700, Mahesh Bandewar wrote:
>>> On Thu, May 19, 2011 at 6:11 PM, Matt Carlson <mcarlson@broadcom.com> wrote:
>>> > Mahesh Bandewar noticed that the features cleanup in commit
>>> > 0da0606f493c5cdab74bdcc96b12f4305ad94085, entitled
>>> > "tg3: Consolidate all netdev feature assignments", mistakenly sets
>>> > NETIF_F_LOOPBACK by default. ?This patch corrects the error.
>>> >
>>> > Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
>>> > ---
>>> > ?drivers/net/tg3.c | ? ?3 ++-
>>> > ?1 files changed, 2 insertions(+), 1 deletions(-)
>>> >
>>> > diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
>>> > index 012ce70..0b78c5d 100644
>>> > --- a/drivers/net/tg3.c
>>> > +++ b/drivers/net/tg3.c
>>> > @@ -15080,6 +15080,8 @@ static int __devinit tg3_init_one(struct pci_dev *pdev,
>>> > ? ? ? ? ? ? ? ? ? ? ? ?features |= NETIF_F_TSO_ECN;
>>> > ? ? ? ?}
>>> >
>>> > + ? ? ? dev->features |= features;
>>> > +
>>> > ? ? ? ?/*
>>> > ? ? ? ? * Add loopback capability only for a subset of devices that support
>>> > ? ? ? ? * MAC-LOOPBACK. Eventually this need to be enhanced to allow INT-PHY
>>> > @@ -15090,7 +15092,6 @@ static int __devinit tg3_init_one(struct pci_dev *pdev,
>>> > ? ? ? ? ? ? ? ?/* Add the loopback capability */
>>> > ? ? ? ? ? ? ? ?features |= NETIF_F_LOOPBACK;
>>> >
>>> > - ? ? ? dev->features |= features;
>>> > ? ? ? ?dev->hw_features |= features;
>>> > ? ? ? ?dev->vlan_features |= features;
>>> I think this line should go up too. Otherwise newly created vlan
>>> device(s) will have spurious loopback bit set.
>> Yes.  You are right.  I thought vlan_features functioned like
>> hw_features.
>
> Probably NETIF_F_LOOPBACK should be forcibly set on VLAN devices when
> underlying device has it enabled. Just a quick thought for discussion.
>
I think that's a good idea for the sake of correctness and should be
done when we enable / disable loopback.

--mahesh..

> Best Regards,
> Michał Mirosław
>