On Sat, Sep 29, 2007 at 05:32:41PM +0200, Patrick McHardy wrote: > > For unicast addresses its not strictly necessary since they may > only be changed under the RTNL anyway. The reason why it takes > the tx_lock is for consistency with multicast address handling, > which can't rely on the RTNL since IPv6 changes them from > BH context. The idea was that the ->set_rx_mode function should > handle both secondary unicast and multicast addresses for > simplicity.
OK, the documentation (which predates USB NIC drivers) disagrees with me and dev->set_multicast will always operate with the xmit lock. This isn't very nice for USB drivers since they have to leave the change request hanging after dev->set_multicast returns. I suppose the one thing that guarantees this will work is the S in USB :) However, at least one USB driver is buggy (kaweth) in not allowing another set_multicast until the previous one is done, which can lead to silent losses of set_multicast calls since it's a void. In any case, coming back to the original question, the RTNL assertion is simply wrong in this case because if we're being called from IPv6 then the RTNL won't even be held. So I think we need to 1) Move the assert into dev_set_promiscuity. 2) Take the TX lock in dev_set_promiscuity. Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
