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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 3C1FAC4743D for ; Tue, 8 Jun 2021 21:33:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1FF4061375 for ; Tue, 8 Jun 2021 21:33:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234302AbhFHVfk (ORCPT ); Tue, 8 Jun 2021 17:35:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233936AbhFHVfg (ORCPT ); Tue, 8 Jun 2021 17:35:36 -0400 Received: from mout-p-102.mailbox.org (mout-p-102.mailbox.org [IPv6:2001:67c:2050::465:102]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 656C8C061574; Tue, 8 Jun 2021 14:33:43 -0700 (PDT) Received: from smtp1.mailbox.org (smtp1.mailbox.org [80.241.60.240]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-102.mailbox.org (Postfix) with ESMTPS id 4G03QB4MylzQk73; Tue, 8 Jun 2021 23:33:38 +0200 (CEST) X-Virus-Scanned: amavisd-new at heinlein-support.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=hauke-m.de; s=MBO0001; t=1623188016; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fSz0m9sPraTKMTobrCNgkrd/L6fxdcYg957KRk67d7E=; b=OPlIvgtJPoNGUNB+gv9VjjjPHWnzOKNOQB0M+ydjt6mcLVSPDz5jvS6JnTM6uKZv7ADMZX GXa/dj9WLC9sS0memtYy6VlMrAWQ2+AiUcTEE7XkyvdXBf3m3H1za4untJTnrvv8g8z7Z1 uE5O1PGp3vg56hZF/dzMEZ8/lt/94H4rRgiobb5JmD48m1f+3LgvYwzg6tKbdHXU/eIE7s DD+hKK/2oGjrcMDhZHpt36YXfJMEW4uIfeWiqhX+L9VLfB0LMmwhiuP6CcNYvQ7JrLQgAN EypAWT744ewduY8JgQSWy5DIP1i6ewugimbsfRkFQdqDZoHJxxdHp4p/ZjQFfQ== Received: from smtp1.mailbox.org ([80.241.60.240]) by spamfilter01.heinlein-hosting.de (spamfilter01.heinlein-hosting.de [80.241.56.115]) (amavisd-new, port 10030) with ESMTP id W8K3dG3pOehM; Tue, 8 Jun 2021 23:33:35 +0200 (CEST) Subject: Re: [PATCH net] net: lantiq: disable interrupt before sheduling NAPI To: Aleksander Jan Bajkowski , davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210608212107.222690-1-olek2@wp.pl> From: Hauke Mehrtens Message-ID: Date: Tue, 8 Jun 2021 23:33:34 +0200 MIME-Version: 1.0 In-Reply-To: <20210608212107.222690-1-olek2@wp.pl> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-MBO-SPAM-Probability: X-Rspamd-Score: -5.11 / 15.00 / 15.00 X-Rspamd-Queue-Id: 8F21B1857 X-Rspamd-UID: 9c61b0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/8/21 11:21 PM, Aleksander Jan Bajkowski wrote: > 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 > --- > 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 36dc3e5f6218..0e10d8aeffe1 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); >