From patchwork Wed Nov 20 03:20:43 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Horman X-Patchwork-Id: 3206041 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D80559F3A0 for ; Wed, 20 Nov 2013 03:32:08 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 018002011C for ; Wed, 20 Nov 2013 03:32:08 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) by mail.kernel.org (Postfix) with ESMTP id 1FC1E200D5 for ; Wed, 20 Nov 2013 03:32:07 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [IPv6:::1]) by mail.linuxfoundation.org (Postfix) with ESMTP id EEAB1C2C; Wed, 20 Nov 2013 03:29:07 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTP id 7C807B57 for ; Wed, 20 Nov 2013 03:28:59 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from kirsty.vergenet.net (kirsty.vergenet.net [202.4.237.240]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 93E1B210D4 for ; Wed, 20 Nov 2013 03:28:58 +0000 (UTC) Received: from ayumi.isobedori.kobe.vergenet.net (p2020-ipbfp1604kobeminato.hyogo.ocn.ne.jp [114.154.85.20]) by kirsty.vergenet.net (Postfix) with ESMTP id 7120326738C; Wed, 20 Nov 2013 14:23:17 +1100 (EST) Received: by ayumi.isobedori.kobe.vergenet.net (Postfix, from userid 7100) id 02C496CE6C7; Wed, 20 Nov 2013 12:23:15 +0900 (JST) From: Simon Horman To: ltsi-dev@lists.linuxfoundation.org Date: Wed, 20 Nov 2013 12:20:43 +0900 Message-Id: <1384917713-15962-526-git-send-email-horms+renesas@verge.net.au> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1384917713-15962-1-git-send-email-horms+renesas@verge.net.au> References: <1384917713-15962-1-git-send-email-horms+renesas@verge.net.au> X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Cc: Magnus Damm Subject: [LTSI-dev] [PATCH ltsi-3.10 525/595] sh_eth: fix napi_{en|dis}able() calls racing against interrupts X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sergei Shtylyov While implementing NAPI for the driver, I overlooked the race conditions where interrupt handler might have called napi_schedule_prep() before napi_enable() was called or after napi_disable() was called. If RX interrupt happens, this would cause the endless interrupts and messages like: sh-eth eth0: ignoring interrupt, status 0x00040000, mask 0x01ff009f. The interrupt wouldn't even be masked by the kernel eventually since the handler would return IRQ_HANDLED all the time. As a fix, move napi_enable() call before request_irq() call and napi_disable() call after free_irq() call. Signed-off-by: Sergei Shtylyov Signed-off-by: David S. Miller (cherry picked from commit d2779e99468fd83ef1493c34f3803fec9aad8345) Signed-off-by: Simon Horman --- drivers/net/ethernet/renesas/sh_eth.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index 16e7b9b..dfb208f 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -1906,11 +1906,13 @@ static int sh_eth_open(struct net_device *ndev) pm_runtime_get_sync(&mdp->pdev->dev); + napi_enable(&mdp->napi); + ret = request_irq(ndev->irq, sh_eth_interrupt, mdp->cd->irq_flags, ndev->name, ndev); if (ret) { dev_err(&ndev->dev, "Can not assign IRQ number\n"); - return ret; + goto out_napi_off; } /* Descriptor set */ @@ -1928,12 +1930,12 @@ static int sh_eth_open(struct net_device *ndev) if (ret) goto out_free_irq; - napi_enable(&mdp->napi); - return ret; out_free_irq: free_irq(ndev->irq, ndev); +out_napi_off: + napi_disable(&mdp->napi); pm_runtime_put_sync(&mdp->pdev->dev); return ret; } @@ -2025,8 +2027,6 @@ static int sh_eth_close(struct net_device *ndev) { struct sh_eth_private *mdp = netdev_priv(ndev); - napi_disable(&mdp->napi); - netif_stop_queue(ndev); /* Disable interrupts by clearing the interrupt mask. */ @@ -2044,6 +2044,8 @@ static int sh_eth_close(struct net_device *ndev) free_irq(ndev->irq, ndev); + napi_disable(&mdp->napi); + /* Free all the skbuffs in the Rx queue. */ sh_eth_ring_free(ndev);