Re: iwlwifi and tx info in skb->cb

["Tomas Winkler" <tomasw@gmail.com>]

On Thu, May 8, 2008 at 1:01 AM, Johannes Berg <johannes@sipsolutions.net> wrote:
> Hi,
>
>  I was just trying to make iwlwifi work again with tx info in skb->cb,
>  but am running into something I don't understand:
>
>  What is a TFD, and why can it have multiple SKBs with a single tx
>  status? I'm referring to:

TFD stands for TX File Descriptor


>  /* One for each TFD */
>  struct iwl3945_tx_info {
>         struct ieee80211_tx_status status;
>         struct sk_buff *skb[MAX_NUM_OF_TBS];
>  };
>
>  I would have expected something like this with 4965 that has aggregation
>  support (and aggregation is reported just once) but here? Confused.

This is for scatter gather. Nothing to do with aggregation. If you get
fragmented frame you can send it out without linearizing in CPU. in
numer of TB - TX buffers (which is limitted bu MAX_NUM_OF_TBS)  But
I'm just over ever explaining :)


Thanks
Tomas

>  johannes
>