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 C0A3DC31E46 for ; Wed, 12 Jun 2019 09:10:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0E122063F for ; Wed, 12 Jun 2019 09:10:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406598AbfFLJKm (ORCPT ); Wed, 12 Jun 2019 05:10:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52128 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405024AbfFLJKl (ORCPT ); Wed, 12 Jun 2019 05:10:41 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 98A3E3092675; Wed, 12 Jun 2019 09:10:41 +0000 (UTC) Received: from localhost (unknown [10.43.2.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1B5161001B0D; Wed, 12 Jun 2019 09:10:38 +0000 (UTC) Date: Wed, 12 Jun 2019 11:10:37 +0200 From: Stanislaw Gruszka To: Lorenzo Bianconi Cc: nbd@nbd.name, kvalo@codeaurora.org, linux-wireless@vger.kernel.org, lorenzo.bianconi@redhat.com Subject: Re: [PATCH v2 2/2] mt76: usb: do not always copy the first part of received frames Message-ID: <20190612091036.GB2965@redhat.com> References: <2ed0b595a12944a8cfea14e066bcc4fa24f0ba44.1559293385.git.lorenzo@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2ed0b595a12944a8cfea14e066bcc4fa24f0ba44.1559293385.git.lorenzo@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.43]); Wed, 12 Jun 2019 09:10:41 +0000 (UTC) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Fri, May 31, 2019 at 11:38:23AM +0200, Lorenzo Bianconi wrote: > Set usb buffer size taking into account skb_shared_info in order to > not always copy the first part of received frames if A-MSDU is enabled > for SG capable devices > > Signed-off-by: Lorenzo Bianconi > --- > drivers/net/wireless/mediatek/mt76/mt76.h | 3 +++ > drivers/net/wireless/mediatek/mt76/usb.c | 12 ++++++++---- > 2 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h > index 74d4edf941d6..7899e9b88b54 100644 > --- a/drivers/net/wireless/mediatek/mt76/mt76.h > +++ b/drivers/net/wireless/mediatek/mt76/mt76.h > @@ -32,6 +32,9 @@ > #define MT_RX_BUF_SIZE 2048 > #define MT_SKB_HEAD_LEN 128 > > +#define MT_BUF_WITH_OVERHEAD(x) \ > + ((x) + SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) > + > 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 2bfc8214c0d8..5081643ce701 100644 > --- a/drivers/net/wireless/mediatek/mt76/usb.c > +++ b/drivers/net/wireless/mediatek/mt76/usb.c > @@ -286,7 +286,7 @@ static int > mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76_queue *q, struct urb *urb, > int nsgs, gfp_t gfp) > { > - int i; > + int i, data_size = SKB_WITH_OVERHEAD(q->buf_size); > > for (i = 0; i < nsgs; i++) { > struct page *page; > @@ -299,7 +299,7 @@ mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76_queue *q, struct urb *urb, > > page = virt_to_head_page(data); > offset = data - page_address(page); > - sg_set_page(&urb->sg[i], page, q->buf_size, offset); > + sg_set_page(&urb->sg[i], page, data_size, offset); > } > > if (i < nsgs) { > @@ -311,7 +311,7 @@ mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76_queue *q, struct urb *urb, > } > > urb->num_sgs = max_t(int, i, urb->num_sgs); > - urb->transfer_buffer_length = urb->num_sgs * q->buf_size, > + urb->transfer_buffer_length = urb->num_sgs * data_size; > sg_init_marker(urb->sg, urb->num_sgs); > > return i ? : -ENOMEM; > @@ -611,8 +611,12 @@ static int mt76u_alloc_rx(struct mt76_dev *dev) > if (!q->entry) > return -ENOMEM; > > - q->buf_size = dev->usb.sg_en ? MT_RX_BUF_SIZE : PAGE_SIZE; > + if (dev->usb.sg_en) > + q->buf_size = MT_BUF_WITH_OVERHEAD(MT_RX_BUF_SIZE); I strongly recommend to not doing this. While this should work in theory creating buffer with size of 2k + some bytes might trigger various bugs in dma mapping or other low level code. And skb_shered_info is needed only in first buffer IIUC. Also this patch seems to make first patch unnecessary except for non sg_en case (in which I think rx AMSDU is broken anyway), so I would prefer just to apply first patch. Stanislaw