Re: [PATCH 7/7] bnx2x: expose HW RX VLAN stripping toggle

On 08/30/2011 08:27 PM, Michał Mirosław wrote:

It seems rather convoluted and unnecessary that you mirror
NETIF_F_HW_VLAN_RX in bp->flags

This mirroring is for the benefit of functions called indirectly from bnx2x_set_features(). They cannot look at dev->features for NETIF_F_HW_VLAN_RX because it's not set before ->ndo_set_features() returns.

and then also in fp->flags.  Are the
fp->flags strictly mirroring hardware state (as in: there is no way
the states can differ in any point in time where the flags are
tested)?

Yes. This is the purpose of the second mirroring of the flag.

For this to be true, the two functions above need to be
called only without releasing a lock between them that is also taken
by receive handler.

The flag propagates from bp->flags to fp->flags between unloading and reloading the NIC. The receive handler cannot run at the time.

Isn't there a flag in the rx descriptor of a
packet that says if VLAN was stripped? (All that flag keeping would be
unnecessary then.)

There is no such flag, AFAIK.

Michal