From patchwork Thu Mar 19 13:04:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229022 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, 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 7ACE6C4332E for ; Thu, 19 Mar 2020 13:28:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53E392098B for ; Thu, 19 Mar 2020 13:28:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624537; bh=x/7Mj1IVLKhB1GyaA358yPJMXxDjNwkvTdsrP80kqqM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=m22I+ofaHFhQUvw4xwPYSdN4clXu9T47O8U500boNrgDPbSQnQQeFa1Z6MtANJzqq 8OMhqBMgTyAfrwCbZlzJ7Mc11qiNJhopBTxJBHpwMh9nPlTD8jgYsWR7pBSGHu1vN0 trfTEvKNGuEHMhUaPox4PeARFF6bh3JXld/Zk83M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730657AbgCSNZh (ORCPT ); Thu, 19 Mar 2020 09:25:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:53254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730655AbgCSNZh (ORCPT ); Thu, 19 Mar 2020 09:25:37 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D45EF2098B; Thu, 19 Mar 2020 13:25:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624336; bh=x/7Mj1IVLKhB1GyaA358yPJMXxDjNwkvTdsrP80kqqM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F5KVKQpupb1nxQCcXN/0PFX/RcayhjdKUrxRZJnSKNdBehJcUUbuQ6lq+n091ilna fIG6jSqruW7X1jqA3TgLHEmxmIssu/jQfU3LkMv5Dz7pqaD57oU80R6x9BNRD/Pi1A JhDHTZCER2IR1hrbxEdUVkrICmb/werMUwtgWBTs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marek Vasut , "David S. Miller" , Lukas Wunner , Petr Stetiar , YueHaibing , Sasha Levin Subject: [PATCH 5.5 27/65] net: ks8851-ml: Fix IRQ handling and locking Date: Thu, 19 Mar 2020 14:04:09 +0100 Message-Id: <20200319123934.961487440@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123926.466988514@linuxfoundation.org> References: <20200319123926.466988514@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 1c9e70c8cc30f..58579baf3f7a0 100644 --- a/drivers/net/ethernet/micrel/ks8851_mll.c +++ b/drivers/net/ethernet/micrel/ks8851_mll.c @@ -513,14 +513,17 @@ 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; } @@ -546,6 +549,7 @@ 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; } @@ -615,6 +619,7 @@ 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); @@ -671,10 +676,9 @@ 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 @@ -688,9 +692,7 @@ 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; }