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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, 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 D1E65C4743C for ; Mon, 21 Jun 2021 16:24:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C237B613F9 for ; Mon, 21 Jun 2021 16:24:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232272AbhFUQ0b (ORCPT ); Mon, 21 Jun 2021 12:26:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:42100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231282AbhFUQZF (ORCPT ); Mon, 21 Jun 2021 12:25:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id F20F76115B; Mon, 21 Jun 2021 16:21:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1624292494; bh=g8o9G1H9mtePYpd3bUS+euMGlKq8E0lRSKm51nh4af8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q77FFhM8Fkh6vYj+jzctA9ka7BPLK944K9rWd+fhC9ZVKeiFDN33q/+Pt3gMDU4u+ 58ZVgKhQanQxzOjYUvtV6Pq8vjEQwC2tiFJWbrvT/CTUU4Fu/4GyyaGIBVUT+Imjkg juuTbbQ+ruEqwPYaGl7QUOOqgEbnPS2hRzx9bU0A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Aleksander Jan Bajkowski , Hauke Mehrtens , "David S. Miller" , Sasha Levin Subject: [PATCH 5.10 021/146] net: lantiq: disable interrupt before sheduling NAPI Date: Mon, 21 Jun 2021 18:14:11 +0200 Message-Id: <20210621154911.990517211@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210621154911.244649123@linuxfoundation.org> References: <20210621154911.244649123@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Aleksander Jan Bajkowski [ Upstream commit f2386cf7c5f4ff5d7b584f5d92014edd7df6c676 ] This patch fixes TX hangs with threaded NAPI enabled. The scheduled NAPI seems to be executed in parallel with the interrupt on second thread. Sometimes it happens that ltq_dma_disable_irq() is executed after xrx200_tx_housekeeping(). The symptom is that TX interrupts are disabled in the DMA controller. As a result, the TX hangs after a few seconds of the iperf test. Scheduling NAPI after disabling interrupts fixes this issue. Tested on Lantiq xRX200 (BT Home Hub 5A). Fixes: 9423361da523 ("net: lantiq: Disable IRQs only if NAPI gets scheduled ") Signed-off-by: Aleksander Jan Bajkowski Acked-by: Hauke Mehrtens Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/lantiq_xrx200.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c index 135ba5b6ae98..3da494df72f3 100644 --- a/drivers/net/ethernet/lantiq_xrx200.c +++ b/drivers/net/ethernet/lantiq_xrx200.c @@ -352,8 +352,8 @@ static irqreturn_t xrx200_dma_irq(int irq, void *ptr) struct xrx200_chan *ch = ptr; if (napi_schedule_prep(&ch->napi)) { - __napi_schedule(&ch->napi); ltq_dma_disable_irq(&ch->dma); + __napi_schedule(&ch->napi); } ltq_dma_ack_irq(&ch->dma); -- 2.30.2