From patchwork Mon Feb 18 20:04:55 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabio Estevam X-Patchwork-Id: 221466 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id DF4C92C0079 for ; Tue, 19 Feb 2013 07:08:29 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757325Ab3BRUI0 (ORCPT ); Mon, 18 Feb 2013 15:08:26 -0500 Received: from co9ehsobe001.messaging.microsoft.com ([207.46.163.24]:21526 "EHLO co9outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757302Ab3BRUIZ (ORCPT ); Mon, 18 Feb 2013 15:08:25 -0500 Received: from mail50-co9-R.bigfish.com (10.236.132.235) by CO9EHSOBE022.bigfish.com (10.236.130.85) with Microsoft SMTP Server id 14.1.225.23; Mon, 18 Feb 2013 20:08:23 +0000 Received: from mail50-co9 (localhost [127.0.0.1]) by mail50-co9-R.bigfish.com (Postfix) with ESMTP id D5E3B2C00EE; Mon, 18 Feb 2013 20:08:23 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: 0 X-BigFish: VS0(zzzz1f42h1ee6h1de0h1202h1e76h1d1ah1d2ahzz8275bhz2dh2a8h668h839hd24he5bhf0ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1155h) Received: from mail50-co9 (localhost.localdomain [127.0.0.1]) by mail50-co9 (MessageSwitch) id 1361218100474011_23120; Mon, 18 Feb 2013 20:08:20 +0000 (UTC) Received: from CO9EHSMHS004.bigfish.com (unknown [10.236.132.250]) by mail50-co9.bigfish.com (Postfix) with ESMTP id 6723848004F; Mon, 18 Feb 2013 20:08:20 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by CO9EHSMHS004.bigfish.com (10.236.130.14) with Microsoft SMTP Server (TLS) id 14.1.225.23; Mon, 18 Feb 2013 20:06:32 +0000 Received: from az84smr01.freescale.net (10.64.34.197) by 039-SN1MMR1-001.039d.mgd.msft.net (10.84.1.13) with Microsoft SMTP Server (TLS) id 14.2.328.11; Mon, 18 Feb 2013 20:06:30 +0000 Received: from fabio-Latitude-E6410.am.freescale.net ([10.29.244.43]) by az84smr01.freescale.net (8.14.3/8.14.0) with ESMTP id r1IK6SSS005664; Mon, 18 Feb 2013 13:06:29 -0700 From: Fabio Estevam To: CC: , , , , , Fabio Estevam Subject: [PATCH v2] net: fec: Fix the disabling of RX interrupt Date: Mon, 18 Feb 2013 17:04:55 -0300 Message-ID: <1361217895-17143-1-git-send-email-fabio.estevam@freescale.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-OriginatorOrg: freescale.com Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The correct way to disable FEC RX interrupt is to clean only the FEC_ENET_RXF bit. Since commit dc975382d2e (net: fec: add napi support to improve proformance) FEC_RX_DISABLED_IMASK is being written to the FEC_IMASK register, which also incorrectly sets other bits as per the definitions below: #define FEC_DEFAULT_IMASK (FEC_ENET_TXF | FEC_ENET_RXF | FEC_ENET_MII) #define FEC_RX_DISABLED_IMASK (FEC_DEFAULT_IMASK & (~FEC_ENET_RXF)) This fixes the following kernel crash: Unable to handle kernel NULL pointer dereference at virtual address 00000002 pgd = 80004000 [00000002] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 0 Not tainted (3.8.0-rc7-next-20130218+ #1192) PC is at fec_enet_interrupt+0xd0/0x354 LR is at fec_enet_interrupt+0xb8/0x354 pc : [<8034592c>] lr : [<80345914>] psr: 60000193 Signed-off-by: Fabio Estevam --- Changes since v1: - Fix it also inside fec_enet_init and fix the kernel crash. drivers/net/ethernet/freescale/fec.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c index 0fe68c4..4eb0201 100644 --- a/drivers/net/ethernet/freescale/fec.c +++ b/drivers/net/ethernet/freescale/fec.c @@ -811,6 +811,7 @@ fec_enet_interrupt(int irq, void *dev_id) struct fec_enet_private *fep = netdev_priv(ndev); uint int_events; irqreturn_t ret = IRQ_NONE; + int reg; do { int_events = readl(fep->hwp + FEC_IEVENT); @@ -821,8 +822,9 @@ fec_enet_interrupt(int irq, void *dev_id) /* Disable the RX interrupt */ if (napi_schedule_prep(&fep->napi)) { - writel(FEC_RX_DISABLED_IMASK, - fep->hwp + FEC_IMASK); + reg = readl(fep->hwp + FEC_IMASK); + reg &= ~FEC_ENET_RXF; + writel(reg, fep->hwp + FEC_IMASK); __napi_schedule(&fep->napi); } } @@ -1598,7 +1600,7 @@ static int fec_enet_init(struct net_device *ndev) struct fec_enet_private *fep = netdev_priv(ndev); struct bufdesc *cbd_base; struct bufdesc *bdp; - int i; + int i, reg; /* Allocate memory for buffer descriptors. */ cbd_base = dma_alloc_coherent(NULL, PAGE_SIZE, &fep->bd_dma, @@ -1628,7 +1630,10 @@ static int fec_enet_init(struct net_device *ndev) ndev->netdev_ops = &fec_netdev_ops; ndev->ethtool_ops = &fec_enet_ethtool_ops; - writel(FEC_RX_DISABLED_IMASK, fep->hwp + FEC_IMASK); + reg = readl(fep->hwp + FEC_IMASK); + reg &= ~FEC_ENET_RXF; + writel(reg, fep->hwp + FEC_IMASK); + netif_napi_add(ndev, &fep->napi, fec_enet_rx_napi, FEC_NAPI_WEIGHT); /* Initialize the receive buffer descriptors. */