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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 3CC09CA9EBB for ; Thu, 24 Oct 2019 06:30:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE16021655 for ; Thu, 24 Oct 2019 06:30:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=nbd.name header.i=@nbd.name header.b="dlj8EmGc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437769AbfJXGa1 (ORCPT ); Thu, 24 Oct 2019 02:30:27 -0400 Received: from nbd.name ([46.4.11.11]:38942 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727750AbfJXGa0 (ORCPT ); Thu, 24 Oct 2019 02:30:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nbd.name; s=20160729; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=xDfZuzNaf4heI4PEB4riPS2rBYIQORF5PqAALeNL0/8=; b=dlj8EmGcaI8lCUzn+PUdZVQRme iHPaSNOulXuYkdsV/kuAppTJjUsB4SKg6x0n4cjwLbXjqX9d/mZ/qc4IhFBc9te53g7wQstX2eTKU B7cTNNJ1Td/1zi4PsT/MYm96H7v416XI2h9sUETMU6lZFslANEEFyqScyNzfjYYdXfNw=; Received: from p4ff1389f.dip0.t-ipconnect.de ([79.241.56.159] helo=nf.local) by ds12 with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1iNWdb-0001El-IX; Thu, 24 Oct 2019 08:30:23 +0200 Subject: Re: [PATCH wireless-drivers 2/2] mt76: dma: fix buffer unmap with non-linear skbs To: Lorenzo Bianconi , kvalo@codeaurora.org Cc: linux-wireless@vger.kernel.org, sgruszka@redhat.com, lorenzo.bianconi@redhat.com, oleksandr@natalenko.name, netdev@vger.kernel.org References: <1f7560e10edd517bfd9d3c0dd9820e6f420726b6.1571868221.git.lorenzo@kernel.org> From: Felix Fietkau Autocrypt: addr=nbd@nbd.name; prefer-encrypt=mutual; keydata= xsDiBEah5CcRBADIY7pu4LIv3jBlyQ/2u87iIZGe6f0f8pyB4UjzfJNXhJb8JylYYRzIOSxh ExKsdLCnJqsG1PY1mqTtoG8sONpwsHr2oJ4itjcGHfn5NJSUGTbtbbxLro13tHkGFCoCr4Z5 Pv+XRgiANSpYlIigiMbOkide6wbggQK32tC20QxUIwCg4k6dtV/4kwEeiOUfErq00TVqIiEE AKcUi4taOuh/PQWx/Ujjl/P1LfJXqLKRPa8PwD4j2yjoc9l+7LptSxJThL9KSu6gtXQjcoR2 vCK0OeYJhgO4kYMI78h1TSaxmtImEAnjFPYJYVsxrhay92jisYc7z5R/76AaELfF6RCjjGeP wdalulG+erWju710Bif7E1yjYVWeA/9Wd1lsOmx6uwwYgNqoFtcAunDaMKi9xVQW18FsUusM TdRvTZLBpoUAy+MajAL+R73TwLq3LnKpIcCwftyQXK5pEDKq57OhxJVv1Q8XkA9Dn1SBOjNB l25vJDFAT9ntp9THeDD2fv15yk4EKpWhu4H00/YX8KkhFsrtUs69+vZQwc0cRmVsaXggRmll dGthdSA8bmJkQG5iZC5uYW1lPsJgBBMRAgAgBQJGoeQnAhsjBgsJCAcDAgQVAggDBBYCAwEC HgECF4AACgkQ130UHQKnbvXsvgCgjsAIIOsY7xZ8VcSm7NABpi91yTMAniMMmH7FRenEAYMa VrwYTIThkTlQzsFNBEah5FQQCACMIep/hTzgPZ9HbCTKm9xN4bZX0JjrqjFem1Nxf3MBM5vN CYGBn8F4sGIzPmLhl4xFeq3k5irVg/YvxSDbQN6NJv8o+tP6zsMeWX2JjtV0P4aDIN1pK2/w VxcicArw0VYdv2ZCarccFBgH2a6GjswqlCqVM3gNIMI8ikzenKcso8YErGGiKYeMEZLwHaxE Y7mTPuOTrWL8uWWRL5mVjhZEVvDez6em/OYvzBwbkhImrryF29e3Po2cfY2n7EKjjr3/141K DHBBdgXlPNfDwROnA5ugjjEBjwkwBQqPpDA7AYPvpHh5vLbZnVGu5CwG7NAsrb2isRmjYoqk wu++3117AAMFB/9S0Sj7qFFQcD4laADVsabTpNNpaV4wAgVTRHKV/kC9luItzwDnUcsZUPdQ f3MueRJ3jIHU0UmRBG3uQftqbZJj3ikhnfvyLmkCNe+/hXhPu9sGvXyi2D4vszICvc1KL4RD aLSrOsROx22eZ26KqcW4ny7+va2FnvjsZgI8h4sDmaLzKczVRIiLITiMpLFEU/VoSv0m1F4B FtRgoiyjFzigWG0MsTdAN6FJzGh4mWWGIlE7o5JraNhnTd+yTUIPtw3ym6l8P+gbvfoZida0 TspgwBWLnXQvP5EDvlZnNaKa/3oBes6z0QdaSOwZCRA3QSLHBwtgUsrT6RxRSweLrcabwkkE GBECAAkFAkah5FQCGwwACgkQ130UHQKnbvW2GgCfTKx80VvCR/PvsUlrvdOLsIgeRGAAn1ee RjMaxwtSdaCKMw3j33ZbsWS4 Message-ID: Date: Thu, 24 Oct 2019 08:30:22 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <1f7560e10edd517bfd9d3c0dd9820e6f420726b6.1571868221.git.lorenzo@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2019-10-24 00:23, Lorenzo Bianconi wrote: > mt76 dma layer is supposed to unmap skb data buffers while keep txwi > mapped on hw dma ring. At the moment mt76 wrongly unmap txwi or does > not unmap data fragments in even positions for non-linear skbs. This > issue may result in hw hangs with A-MSDU if the system relies on IOMMU > or SWIOTLB. Fix this behaviour properly unmapping data fragments on > non-linear skbs. > > Fixes: 17f1de56df05 ("mt76: add common code shared between multiple chipsets") > Signed-off-by: Lorenzo Bianconi > --- > drivers/net/wireless/mediatek/mt76/dma.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c > index c747eb24581c..8c27956875e7 100644 > --- a/drivers/net/wireless/mediatek/mt76/dma.c > +++ b/drivers/net/wireless/mediatek/mt76/dma.c > @@ -93,11 +93,14 @@ static void > mt76_dma_tx_cleanup_idx(struct mt76_dev *dev, struct mt76_queue *q, int idx, > struct mt76_queue_entry *prev_e) > { > - struct mt76_queue_entry *e = &q->entry[idx]; > __le32 __ctrl = READ_ONCE(q->desc[idx].ctrl); > + struct mt76_queue_entry *e = &q->entry[idx]; > u32 ctrl = le32_to_cpu(__ctrl); > + bool mcu = e->skb && !e->txwi; > + bool first = e->skb == DMA_DUMMY_DATA || e->txwi == DMA_DUMMY_DATA || > + (e->skb && !skb_is_nonlinear(e->skb)); It seems to me that these conditions could be true not just for the first entry, but also following entries except for the last one. I think we should add a 'bool has_txwi' field in struct mt76_queue_entry to indicate that the first dma address points to a txwi that should not be unmapped. - Felix