Re: IGMP Join dropping multicast packets

[David Miller <davem@davemloft.net>]

From: "Brandeburg, Jesse" <jesse.brandeburg@intel.com>
Date: Wed, 18 Mar 2009 10:24:18 -0700 (Pacific Daylight Time)

> Interesting, this code has been there for eons (and probably this 
> behavior) but that doesn't mean its not a problem.
> 
> We are in the process of figuring out if there are any hardware corner 
> cases to changing this code (particularly in e1000)
> 
> Initial thoughts are:
> 1) kcalloc an array that we then populate with the hash functions, and 
>    then program every location only once (never flush)
> 2) only program a single hash value each time a multicast is added (bad 
>    because we can't tell the difference in the list since the last time 
>    the OS gave us the list)
> 
> It really seems like this should be fixable, and I agree that the driver 
> behavior is far from optimal, however well entrenched.

Just do what tg3 does to fix this now, get fancy and "beautiful"
later.