Re: [RFC/RFT v2] mac80211: Add NEED_ALIGNED4_SKBS hw flag

[Johannes Berg <johannes@sipsolutions.net>]

On Fri, 2015-12-18 at 12:57 +0100, Janusz Dziedzic wrote:
> HW/driver should set NEED_ALIGNED4_SKBS flag in case require
> aligned skbs to four-byte boundaries.
> 
> Before we have to do memmove() in the driver before
> pass this to HW and memmove() back in tx completion.
> This patch allow to save CPU and skip such memmoves.
> For each skb we call memmove(ieee80211_hdrsize()) twice.
> 
> Currently this was tested with ath9k, both hw/sw crypt for
> tkip/ccmp.
> For sure more tests required (eg. fast path isn't used for
> ath9k STA, wep sw crypt).
> 
> Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
> ---
>  include/net/mac80211.h     |  4 ++++
>  net/mac80211/debugfs.c     |  1 +
>  net/mac80211/ieee80211_i.h |  1 +
>  net/mac80211/sta_info.h    |  4 ++--
>  net/mac80211/tkip.c        | 15 ++++++++++++---
>  net/mac80211/tx.c          | 38 +++++++++++++++++++++++++++++++++---
> --
>  net/mac80211/util.c        |  7 ++++++-
>  net/mac80211/wep.c         | 11 ++++++-----
>  net/mac80211/wep.h         |  1 +
>  net/mac80211/wpa.c         | 14 ++++++--------
>  10 files changed, 72 insertions(+), 24 deletions(-)
> 
Btw, how can you get away without changing the status path?

johannes