Ben Greear wrote:

Patrick McHardy wrote:

quoted

Fix sky2 disabling VLAN completely when the first vid is unregistered.

For some reason the VLAN code insists on the driver providing a
vlan_rx_kill_vid function even if only NETIF_F_HW_VLAN_RX and not
NETIF_F_HW_VLAN_FILTER is set, so this patch keeps an empty
function. This seems to be a bug though, vlan_rx_add_vid is only
required with NETIF_F_HW_VLAN_FILTER. Ben?
  

I believe DaveM did most of the vlan hw-accel work.  It would be easy
enough to check
for a null function before calling the vlan_rx_kill_vid function and
relax the checks
based on the flags, but there may be valid reasons to keep this as is. 

Most drivers are using vlan_rx_kill_vid to remove a vid from the
group under their local local lock, which seems unnecessary since
the VLAN code calls synchronize_net before freeing it and also
does the removal itself. A few others have empty functions and
8139cp seems to have the same bug as sky2. In all cases it doesn't
seem to be needed for drivers without NETIF_F_HW_VLAN_FILTER.