From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD42EC31E44 for ; Fri, 14 Jun 2019 11:14:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B86DA2133D for ; Fri, 14 Jun 2019 11:14:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727216AbfFNLOT (ORCPT ); Fri, 14 Jun 2019 07:14:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32944 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727164AbfFNLOS (ORCPT ); Fri, 14 Jun 2019 07:14:18 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7FBEB10C94; Fri, 14 Jun 2019 11:14:18 +0000 (UTC) Received: from localhost (ovpn-204-80.brq.redhat.com [10.40.204.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1D1F81A8F1; Fri, 14 Jun 2019 11:14:15 +0000 (UTC) Date: Fri, 14 Jun 2019 13:14:15 +0200 From: Stanislaw Gruszka To: Lorenzo Bianconi Cc: Lorenzo Bianconi , kvalo@codeaurora.org, linux-wireless@vger.kernel.org, nbd@nbd.name, johannes@sipsolutions.net Subject: Re: [PATCH v3 wireless-drivers 1/3] mt76: usb: fix rx A-MSDU support Message-ID: <20190614111414.GB17298@redhat.com> References: <66fc02e45fb5ce0d6176395b5ac43acbd53b3e66.1560461404.git.lorenzo@kernel.org> <20190614072449.GA3395@redhat.com> <20190614101115.GA2669@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190614101115.GA2669@localhost.localdomain> User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 14 Jun 2019 11:14:18 +0000 (UTC) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Fri, Jun 14, 2019 at 12:11:17PM +0200, Lorenzo Bianconi wrote: > > On Thu, Jun 13, 2019 at 11:43:11PM +0200, Lorenzo Bianconi wrote: > > > Commit f8f527b16db5 ("mt76: usb: use EP max packet aligned buffer sizes > > > for rx") breaks A-MSDU support. When A-MSDU is enable the device can > > > receive frames up to q->buf_size but they will be discarded in > > > mt76u_process_rx_entry since there is no enough room for > > > skb_shared_info. Fix the issue reallocating the skb and copying in the > > > linear area the first 128B of the received frames and in the frag_list > > > the remaining part. > > > > > > Fixes: f8f527b16db5 ("mt76: usb: use EP max packet aligned buffer sizes for rx") > > > Signed-off-by: Lorenzo Bianconi > > > --- > > > drivers/net/wireless/mediatek/mt76/mt76.h | 1 + > > > drivers/net/wireless/mediatek/mt76/usb.c | 49 ++++++++++++++++++----- > > > 2 files changed, 41 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h > > > index 8ecbf81a906f..889b76deb703 100644 > > > --- a/drivers/net/wireless/mediatek/mt76/mt76.h > > > +++ b/drivers/net/wireless/mediatek/mt76/mt76.h > > > @@ -30,6 +30,7 @@ > > > #define MT_TX_RING_SIZE 256 > > > #define MT_MCU_RING_SIZE 32 > > > #define MT_RX_BUF_SIZE 2048 > > > +#define MT_SKB_HEAD_LEN 128 > > > > > > struct mt76_dev; > > > struct mt76_wcid; > > > diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c > > > index bbaa1365bbda..12d60d31cb51 100644 > > > --- a/drivers/net/wireless/mediatek/mt76/usb.c > > > +++ b/drivers/net/wireless/mediatek/mt76/usb.c > > > @@ -429,6 +429,45 @@ static int mt76u_get_rx_entry_len(u8 *data, u32 data_len) > > > return dma_len; > > > } > > > > > > +static struct sk_buff * > > > +mt76u_build_rx_skb(u8 *data, int len, int buf_size) > > > +{ > > > + struct sk_buff *skb; > > > + > > > + if (SKB_WITH_OVERHEAD(buf_size) < MT_DMA_HDR_LEN + len) { > > > + struct page *page; > > > + int offset; > > > + > > > + /* slow path, not enough space for data and > > > + * skb_shared_info > > > + */ > > > + skb = alloc_skb(MT_SKB_HEAD_LEN, GFP_ATOMIC); > > > + if (!skb) > > > + return NULL; > > > + > > > + skb_put_data(skb, data + MT_DMA_HDR_LEN, MT_SKB_HEAD_LEN); > > > > I looked how rx amsdu is processed in mac80211 and it is decomposed and > > copied into newly allocated individual skb's, see ieee80211_amsdu_to_8023s() > > > > So copy L3 & L4 headers doesn't do anything good here, actually seems to > > be better to have them in frag as __ieee80211_amsdu_copy_frag() do some > > magic to avid copy. > > Looking at __ieee80211_amsdu_copy() now I got why other drivers copy hdrlen + > 8, thx :) > In our case reuse_frag is true in __ieee80211_amsdu_copy, so we will end up I don't think reuse_frag is true in our case since skb->head_frag is not set when we use alloc_skb(). Stanislaw