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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 58183C31E46 for ; Wed, 12 Jun 2019 09:53:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 35AD020896 for ; Wed, 12 Jun 2019 09:53:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437738AbfFLJxI (ORCPT ); Wed, 12 Jun 2019 05:53:08 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:39892 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437415AbfFLJxI (ORCPT ); Wed, 12 Jun 2019 05:53:08 -0400 Received: by mail-wr1-f65.google.com with SMTP id x4so13523762wrt.6 for ; Wed, 12 Jun 2019 02:53:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=VVhE7iZd36zR1LOe4i7mf8BRoSS45j81UOesfJcvyiA=; b=h8yc92XxmkSg1PzCyfukGwjh1H1hWYBGyshJuNDSa6IfjQYnhMApJLM+JFU0JlFCfM Ore3bhibuhiak6eWou6xzpqqzC/mlN5yHLOteKLRY5Lc210/6X3x15QZ8iLqMJbR3/pV NQArXGeVVjC5HPonPXe7gtboEsQ9L3Sg5BqxnrmXDg2Oy/+QUb9BpGT4SH1RFcc2vYcF 7KcJXA38SnfJVge9ET9lQO108+H3UWaSfGUrKzMex6HrE3wZYdL63oesZ5SLpSX+StmZ rkUTpG1JPq5Hff+AeOEd2alWBR28Gtrd2eX3J5JkEzExi8koHW2RepUixcqrPC9FULDX TCTw== X-Gm-Message-State: APjAAAVlz1ehYYGSUCXeiav91awx0hTKzZNz170pT6RBGd25CdnlYpCN xAhGRo3NWlTgo710L2VRg+TZxg== X-Google-Smtp-Source: APXvYqylaKKe04PWmg6OFzVdLzP0QmzyjGVKfeBvl1N4aC+29oVkWS24CzujtOUm0kaIWTNY4QCSRg== X-Received: by 2002:adf:f909:: with SMTP id b9mr20595666wrr.119.1560333185919; Wed, 12 Jun 2019 02:53:05 -0700 (PDT) Received: from localhost.localdomain (nat-pool-mxp-t.redhat.com. [149.6.153.186]) by smtp.gmail.com with ESMTPSA id s12sm3681516wmh.34.2019.06.12.02.53.05 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 12 Jun 2019 02:53:05 -0700 (PDT) Date: Wed, 12 Jun 2019 11:53:03 +0200 From: Lorenzo Bianconi To: Stanislaw Gruszka Cc: Lorenzo Bianconi , nbd@nbd.name, kvalo@codeaurora.org, linux-wireless@vger.kernel.org Subject: Re: [PATCH v2 2/2] mt76: usb: do not always copy the first part of received frames Message-ID: <20190612095302.GD8107@localhost.localdomain> References: <2ed0b595a12944a8cfea14e066bcc4fa24f0ba44.1559293385.git.lorenzo@kernel.org> <20190612091036.GB2965@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Km1U/tdNT/EmXiR1" Content-Disposition: inline In-Reply-To: <20190612091036.GB2965@redhat.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org --Km1U/tdNT/EmXiR1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > On Fri, May 31, 2019 at 11:38:23AM +0200, Lorenzo Bianconi wrote: [...] > > } > > =20 > > urb->num_sgs =3D max_t(int, i, urb->num_sgs); > > - urb->transfer_buffer_length =3D urb->num_sgs * q->buf_size, > > + urb->transfer_buffer_length =3D urb->num_sgs * data_size; > > sg_init_marker(urb->sg, urb->num_sgs); > > =20 > > return i ? : -ENOMEM; > > @@ -611,8 +611,12 @@ static int mt76u_alloc_rx(struct mt76_dev *dev) > > if (!q->entry) > > return -ENOMEM; > > =20 > > - q->buf_size =3D dev->usb.sg_en ? MT_RX_BUF_SIZE : PAGE_SIZE; > > + if (dev->usb.sg_en) > > + q->buf_size =3D MT_BUF_WITH_OVERHEAD(MT_RX_BUF_SIZE); >=20 > 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. even in practice actually :) but we can be more cautious since probably cop= ying the first 128B will not make any difference >=20 > And skb_shered_info is needed only in first buffer IIUC. >=20 > 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. I do not think rx AMSDU is broken for non sg_en case since the max rx value allowed should be 3839 IIRC and we alloc one page in this case Regards, Lorenzo >=20 > Stanislaw >=20 --Km1U/tdNT/EmXiR1 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCXQDLewAKCRA6cBh0uS2t rB0vAP9wHIDCzMk96w27Q43y4bLilwtfv6S0/moHO8BdQFcNNQD/b3M4xvKXhmZz MlPFDgseZcnXMGhZXVaZ/DRaK9L8mQ0= =3Ukz -----END PGP SIGNATURE----- --Km1U/tdNT/EmXiR1--