From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:45850 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727765AbeKIHbU (ORCPT ); Fri, 9 Nov 2018 02:31:20 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Fainelli , "David S. Miller" Subject: [PATCH 3.18 014/144] net: systemport: Fix wake-up interrupt race during resume Date: Thu, 8 Nov 2018 13:49:45 -0800 Message-Id: <20181108215055.824490259@linuxfoundation.org> In-Reply-To: <20181108215054.826084593@linuxfoundation.org> References: <20181108215054.826084593@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Fainelli [ Upstream commit 45ec318578c0c22a11f5b9927d064418e1ab1905 ] The AON_PM_L2 is normally used to trigger and identify the source of a wake-up event. Since the RX_SYS clock is no longer turned off, we also have an interrupt being sent to the SYSTEMPORT INTRL_2_0 controller, and that interrupt remains active up until the magic packet detector is disabled which happens much later during the driver resumption. The race happens if we have a CPU that is entering the SYSTEMPORT INTRL2_0 handler during resume, and another CPU has managed to clear the wake-up interrupt during bcm_sysport_resume_from_wol(). In that case, we have the first CPU stuck in the interrupt handler with an interrupt cause that has been cleared under its feet, and so we keep returning IRQ_NONE and we never make any progress. This was not a problem before because we would always turn off the RX_SYS clock during WoL, so the SYSTEMPORT INTRL2_0 would also be turned off as well, thus not latching the interrupt. The fix is to make sure we do not enable either the MPD or BRCM_TAG_MATCH interrupts since those are redundant with what the AON_PM_L2 interrupt controller already processes and they would cause such a race to occur. Fixes: bb9051a2b230 ("net: systemport: Add support for WAKE_FILTER") Fixes: 83e82f4c706b ("net: systemport: add Wake-on-LAN support") Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/broadcom/bcmsysport.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -769,14 +769,22 @@ static void bcm_sysport_resume_from_wol( { u32 reg; - /* Stop monitoring MPD interrupt */ - intrl2_0_mask_set(priv, INTRL2_0_MPD); - /* Clear the MagicPacket detection logic */ reg = umac_readl(priv, UMAC_MPD_CTRL); reg &= ~MPD_EN; umac_writel(priv, reg, UMAC_MPD_CTRL); + reg = intrl2_0_readl(priv, INTRL2_CPU_STATUS); + if (reg & INTRL2_0_MPD) + netdev_info(priv->netdev, "Wake-on-LAN (MPD) interrupt!\n"); + + if (reg & INTRL2_0_BRCM_MATCH_TAG) { + reg = rxchk_readl(priv, RXCHK_BRCM_TAG_MATCH_STATUS) & + RXCHK_BRCM_TAG_MATCH_MASK; + netdev_info(priv->netdev, + "Wake-on-LAN (filters 0x%02x) interrupt!\n", reg); + } + netif_dbg(priv, wol, priv->netdev, "resumed from WOL\n"); } @@ -809,11 +817,6 @@ static irqreturn_t bcm_sysport_rx_isr(in if (priv->irq0_stat & INTRL2_0_TX_RING_FULL) bcm_sysport_tx_reclaim_all(priv); - if (priv->irq0_stat & INTRL2_0_MPD) { - netdev_info(priv->netdev, "Wake-on-LAN interrupt!\n"); - bcm_sysport_resume_from_wol(priv); - } - return IRQ_HANDLED; } @@ -1786,9 +1789,6 @@ static int bcm_sysport_suspend_to_wol(st /* UniMAC receive needs to be turned on */ umac_enable_set(priv, CMD_RX_EN, 1); - /* Enable the interrupt wake-up source */ - intrl2_0_mask_clear(priv, INTRL2_0_MPD); - netif_dbg(priv, wol, ndev, "entered WOL mode\n"); return 0;