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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A6D76C3F2D1 for ; Thu, 5 Mar 2020 17:16:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7AD69207FD for ; Thu, 5 Mar 2020 17:16:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583428616; bh=fnujKJ1/4oO0PNPwquSQpLSJH6HeF+U1tw4Tv1etEbM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=CkyTvlu8Zl3CikJwbTpXftJaptfDKHl9CmTpV8ECaetBjyISkyQqB1jxH39rYNlIA ln0oR3TUsRboe46Kx3UtDvnndKK27dkU799eAc+6Cxt9SXPo8EasvG9ES9qiA/75lU yW9hBClITAkwYOBebJUDrfxqBgHgLkd3Fwpy7AqE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727934AbgCERQz (ORCPT ); Thu, 5 Mar 2020 12:16:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:43194 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728399AbgCERQK (ORCPT ); Thu, 5 Mar 2020 12:16:10 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B36BC21744; Thu, 5 Mar 2020 17:16:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583428569; bh=fnujKJ1/4oO0PNPwquSQpLSJH6HeF+U1tw4Tv1etEbM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zFkZJK1IAukFRnpkhszZTAATu2G2XjBKuo73BC76WwNUVzuyKwpBFgA0LjYlGPglO Apx4TKGnqhYqdFECwoBkmHTCgy104ysr5B9uQvpZe1rlNO49yhs6UnqTcf7YqesnSi Vtg+wgTgTDJo8aw4UbwyuagCw+VmbJ8EkvRs7Qjg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Marek Vasut , "David S . Miller" , Lukas Wunner , Petr Stetiar , YueHaibing , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 08/12] net: ks8851-ml: Fix IRQ handling and locking Date: Thu, 5 Mar 2020 12:15:55 -0500 Message-Id: <20200305171559.30422-8-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200305171559.30422-1-sashal@kernel.org> References: <20200305171559.30422-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marek Vasut [ Upstream commit 44343418d0f2f623cb9da6f5000df793131cbe3b ] The KS8851 requires that packet RX and TX are mutually exclusive. Currently, the driver hopes to achieve this by disabling interrupt from the card by writing the card registers and by disabling the interrupt on the interrupt controller. This however is racy on SMP. Replace this approach by expanding the spinlock used around the ks_start_xmit() TX path to ks_irq() RX path to assure true mutual exclusion and remove the interrupt enabling/disabling, which is now not needed anymore. Furthermore, disable interrupts also in ks_net_stop(), which was missing before. Note that a massive improvement here would be to re-use the KS8851 driver approach, which is to move the TX path into a worker thread, interrupt handling to threaded interrupt, and synchronize everything with mutexes, but that would be a much bigger rework, for a separate patch. Signed-off-by: Marek Vasut Cc: David S. Miller Cc: Lukas Wunner Cc: Petr Stetiar Cc: YueHaibing Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/micrel/ks8851_mll.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/micrel/ks8851_mll.c b/drivers/net/ethernet/micrel/ks8851_mll.c index 8dc1f0277117d..cc44143f86a5e 100644 --- a/drivers/net/ethernet/micrel/ks8851_mll.c +++ b/drivers/net/ethernet/micrel/ks8851_mll.c @@ -866,14 +866,17 @@ static irqreturn_t ks_irq(int irq, void *pw) { struct net_device *netdev = pw; struct ks_net *ks = netdev_priv(netdev); + unsigned long flags; u16 status; + spin_lock_irqsave(&ks->statelock, flags); /*this should be the first in IRQ handler */ ks_save_cmd_reg(ks); status = ks_rdreg16(ks, KS_ISR); if (unlikely(!status)) { ks_restore_cmd_reg(ks); + spin_unlock_irqrestore(&ks->statelock, flags); return IRQ_NONE; } @@ -899,6 +902,7 @@ static irqreturn_t ks_irq(int irq, void *pw) ks->netdev->stats.rx_over_errors++; /* this should be the last in IRQ handler*/ ks_restore_cmd_reg(ks); + spin_unlock_irqrestore(&ks->statelock, flags); return IRQ_HANDLED; } @@ -968,6 +972,7 @@ static int ks_net_stop(struct net_device *netdev) /* shutdown RX/TX QMU */ ks_disable_qmu(ks); + ks_disable_int(ks); /* set powermode to soft power down to save power */ ks_set_powermode(ks, PMECR_PM_SOFTDOWN); @@ -1024,10 +1029,9 @@ static netdev_tx_t ks_start_xmit(struct sk_buff *skb, struct net_device *netdev) { netdev_tx_t retv = NETDEV_TX_OK; struct ks_net *ks = netdev_priv(netdev); + unsigned long flags; - disable_irq(netdev->irq); - ks_disable_int(ks); - spin_lock(&ks->statelock); + spin_lock_irqsave(&ks->statelock, flags); /* Extra space are required: * 4 byte for alignment, 4 for status/length, 4 for CRC @@ -1041,9 +1045,7 @@ static netdev_tx_t ks_start_xmit(struct sk_buff *skb, struct net_device *netdev) dev_kfree_skb(skb); } else retv = NETDEV_TX_BUSY; - spin_unlock(&ks->statelock); - ks_enable_int(ks); - enable_irq(netdev->irq); + spin_unlock_irqrestore(&ks->statelock, flags); return retv; } -- 2.20.1