Return-path: Received: from arrakis.dune.hu ([78.24.191.176]:54095 "EHLO arrakis.dune.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754382AbbLQJlQ (ORCPT ); Thu, 17 Dec 2015 04:41:16 -0500 Subject: Re: [RFC/RFT 1/2] mac80211: Add NEED_ALIGNED4_SKBS hw flag To: Janusz Dziedzic , linux-wireless@vger.kernel.org References: <1450344029-5296-1-git-send-email-janusz.dziedzic@tieto.com> Cc: johannes@sipsolutions.net From: Felix Fietkau Message-ID: <567282C9.501@openwrt.org> (sfid-20151217_104221_847479_2D0F90E4) Date: Thu, 17 Dec 2015 10:39:21 +0100 MIME-Version: 1.0 In-Reply-To: <1450344029-5296-1-git-send-email-janusz.dziedzic@tieto.com> Content-Type: text/plain; charset=utf-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2015-12-17 10:20, 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 called memmove(ieee80211_hdrsize()) twice. > > Currently this was tested with ath9k, both hw/sw crypt for > tkip/ccmp. > For sure more tests required. > > Signed-off-by: Janusz Dziedzic Nice. By the way, this alignment requirement is not ath9k specific - mt76 (currently out-of-tree), mt7601u and rt2x00 can use this as well. - Felix