From 93966b715b32a783a1641f5a385901bbfab04733 Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Fri, 14 Oct 2016 14:14:35 -0500 Subject: [PATCH] net: qcom/emac: disable interrupts before calling phy_disconnect There is a race condition that can occur if EMAC interrupts are enabled when phy_disconnect() is called. phy_disconnect() sets adjust_link to NULL. When an interrupt occurs, the ISR might call phy_mac_interrupt(), which wakes up the workqueue function phy_state_machine(). This function might reference adjust_link, thereby causing a null pointer exception. Signed-off-by: Timur Tabi Signed-off-by: David S. Miller --- drivers/net/ethernet/qualcomm/emac/emac-mac.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/qualcomm/emac/emac-mac.c b/drivers/net/ethernet/qualcomm/emac/emac-mac.c index e97968ed4b8f..6fb3bee904d3 100644 --- a/drivers/net/ethernet/qualcomm/emac/emac-mac.c +++ b/drivers/net/ethernet/qualcomm/emac/emac-mac.c @@ -1021,14 +1021,18 @@ void emac_mac_down(struct emac_adapter *adpt) napi_disable(&adpt->rx_q.napi); phy_stop(adpt->phydev); - phy_disconnect(adpt->phydev); - /* disable mac irq */ + /* Interrupts must be disabled before the PHY is disconnected, to + * avoid a race condition where adjust_link is null when we get + * an interrupt. + */ writel(DIS_INT, adpt->base + EMAC_INT_STATUS); writel(0, adpt->base + EMAC_INT_MASK); synchronize_irq(adpt->irq.irq); free_irq(adpt->irq.irq, &adpt->irq); + phy_disconnect(adpt->phydev); + emac_mac_reset(adpt); emac_tx_q_descs_free(adpt); -- 2.20.1