Re: [Bugme-new] [Bug 11144] New: dhcp doesn't work with iwl4965

[Patrick McHardy <kaber@trash.net>]

Tomas Winkler wrote:
> On Thu, Jul 24, 2008 at 11:58 AM, Patrick McHardy <kaber@trash.net> wrote:
>> David Miller wrote:
>>> From: Patrick McHardy <kaber@trash.net>
>>> Date: Wed, 23 Jul 2008 18:25:48 +0200
>>>
>>>> We can't fit them into the cb together, I don't see a way to
>>>> shrink ieee80211_tx_info.
>>>>
>>>> Maybe one of the wireless folks can suggest something? Is it
>>>> really necessary to pass the full struct ieee80211_tx_info
>>>> through the qdisc layer, or could the struct be split? It
>>>> needs to find a way to co-exist peacefully with qdiscs'
>>>> skb->cb usage.
>>> This is another area that got mangled up in the ->select_queue()
>>> conversion of the WME bits, but in another aspect this problem
>>> existed beforehand as well.
>>>
>>> Specifically, when RX packets get requeued out to transmit in
>>> the code in net/mac80211/rx.c that resends packets back out the
>>> wireless device by setting a bit in the SKB CB then calling
>>> dev_queue_xmit().
>>>
>>> That's completely illegal :-)
>> It seems its doing even more illegal things that were also
>> present previously. The ieee80211_master_start_xmit function
>> expects to get a valid IEEE80211_SKB_CB, which means it
>> expects it to survive through the entire qdisc layer. I'm
>> not sure how packets get to the master device from the
>> subifs though, so I might be wrong.
>>
> Isn't this time to make 802.11 native?


You mean by making these things real skb members? I hope you're
not talking about the entire 48 bytes? :)