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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 40CADC2D0D1 for ; Sun, 29 Dec 2019 18:01:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D4A421D7E for ; Sun, 29 Dec 2019 18:01:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577642513; bh=u53Zuqm+MdMRAsLTirKk63Da+BvkVOKaahC09Hyss4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=n/FPHq8I/bnBD9E5r3KKZu3B3u1o4tiKlxs9sN6wl23l7GVRALdgIe0+dRtgndLna x/9JBMlt7lcicy6vXwQzcGCruM59Qe9QsZY6O6CJD+M9uch1JyxnpwoeSW2uknW2V4 lRD/pmoMnHlOKXUWszyD7HzMUmWh++H2FgHuMCk0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732977AbfL2Rzp (ORCPT ); Sun, 29 Dec 2019 12:55:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:44710 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732972AbfL2Rzo (ORCPT ); Sun, 29 Dec 2019 12:55:44 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 99262206DB; Sun, 29 Dec 2019 17:55:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577642144; bh=u53Zuqm+MdMRAsLTirKk63Da+BvkVOKaahC09Hyss4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=je7fUUOL+uIGIMLEJfibyb9zecGsXhW1h+qzAdBzjgmqOn3YKlQo2C7MzLEyoYfLe dEs9Ap/AYjBTZtUKGziy1yDOWdUWALcBzhxgr/GZdlJ/lP56XWuGvIak/uSCQacLDK woa+MrXtUCFCTThk7/WDd+jdqwdYcemMzWch1OAs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Lobakin , Luca Coelho , Nicholas Johnson , Edward Cree , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 359/434] net: wireless: intel: iwlwifi: fix GRO_NORMAL packet stalling Date: Sun, 29 Dec 2019 18:26:52 +0100 Message-Id: <20191229172725.816512424@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191229172702.393141737@linuxfoundation.org> References: <20191229172702.393141737@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexander Lobakin [ Upstream commit b167191e2a851cb2e4c6ef8b91c83ff73ef41872 ] Commit 6570bc79c0df ("net: core: use listified Rx for GRO_NORMAL in napi_gro_receive()") has applied batched GRO_NORMAL packets processing to all napi_gro_receive() users, including mac80211-based drivers. However, this change has led to a regression in iwlwifi driver [1][2] as it is required for NAPI users to call napi_complete_done() or napi_complete() and the end of every polling iteration, whilst iwlwifi doesn't use NAPI scheduling at all and just calls napi_gro_flush(). In that particular case, packets which have not been already flushed from napi->rx_list stall in it until at least next Rx cycle. Fix this by adding a manual flushing of the list to iwlwifi driver right before napi_gro_flush() call to mimic napi_complete() logics. I prefer to open-code gro_normal_list() rather than exporting it for 2 reasons: * to prevent from using it and napi_gro_flush() in any new drivers, as it is the *really* bad way to use NAPI that should be avoided; * to keep gro_normal_list() static and don't lose any CC optimizations. I also don't add the "Fixes:" tag as the mentioned commit was only a trigger that only exposed an improper usage of NAPI in this particular driver. [1] https://lore.kernel.org/netdev/PSXP216MB04388962C411CD0B17A86F47804A0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM [2] https://bugzilla.kernel.org/show_bug.cgi?id=205647 Signed-off-by: Alexander Lobakin Acked-by: Luca Coelho Reported-by: Nicholas Johnson Tested-by: Nicholas Johnson Reviewed-by: Edward Cree Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c index 19dd075f2f63..041dd75ac72b 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c @@ -1429,6 +1429,7 @@ out_err: static void iwl_pcie_rx_handle(struct iwl_trans *trans, int queue) { struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans); + struct napi_struct *napi; struct iwl_rxq *rxq; u32 r, i, count = 0; bool emergency = false; @@ -1534,8 +1535,16 @@ out: if (unlikely(emergency && count)) iwl_pcie_rxq_alloc_rbs(trans, GFP_ATOMIC, rxq); - if (rxq->napi.poll) - napi_gro_flush(&rxq->napi, false); + napi = &rxq->napi; + if (napi->poll) { + if (napi->rx_count) { + netif_receive_skb_list(&napi->rx_list); + INIT_LIST_HEAD(&napi->rx_list); + napi->rx_count = 0; + } + + napi_gro_flush(napi, false); + } iwl_pcie_rxq_restock(trans, rxq); } -- 2.20.1