From 5b1d9c17a3e0c16e1c9adf9c8a89f2735cb6dff8 Mon Sep 17 00:00:00 2001 From: Hayes Wang Date: Fri, 22 Nov 2019 16:21:09 +0800 Subject: [PATCH] r8152: avoid to call napi_disable twice Call napi_disable() twice would cause dead lock. There are three situations may result in the issue. 1. rtl8152_pre_reset() and set_carrier() are run at the same time. 2. Call rtl8152_set_tunable() after rtl8152_close(). 3. Call rtl8152_set_ringparam() after rtl8152_close(). For #1, use the same solution as commit 84811412464d ("r8152: Re-order napi_disable in rtl8152_close"). For #2 and #3, add checking the flag of IFF_UP and using napi_disable/napi_enable during mutex. Signed-off-by: Hayes Wang Signed-off-by: David S. Miller --- drivers/net/usb/r8152.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index 4d34c01826f301..b2507c59ba8b38 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -4552,10 +4552,10 @@ static int rtl8152_pre_reset(struct usb_interface *intf) netif_stop_queue(netdev); tasklet_disable(&tp->tx_tl); - napi_disable(&tp->napi); clear_bit(WORK_ENABLE, &tp->flags); usb_kill_urb(tp->intr_urb); cancel_delayed_work_sync(&tp->schedule); + napi_disable(&tp->napi); if (netif_carrier_ok(netdev)) { mutex_lock(&tp->control); tp->rtl_ops.disable(tp); @@ -4673,7 +4673,7 @@ static int rtl8152_system_resume(struct r8152 *tp) netif_device_attach(netdev); - if (netif_running(netdev) && netdev->flags & IFF_UP) { + if (netif_running(netdev) && (netdev->flags & IFF_UP)) { tp->rtl_ops.up(tp); netif_carrier_off(netdev); set_bit(WORK_ENABLE, &tp->flags); @@ -5244,9 +5244,15 @@ static int rtl8152_set_tunable(struct net_device *netdev, } if (tp->rx_copybreak != val) { - napi_disable(&tp->napi); - tp->rx_copybreak = val; - napi_enable(&tp->napi); + if (netdev->flags & IFF_UP) { + mutex_lock(&tp->control); + napi_disable(&tp->napi); + tp->rx_copybreak = val; + napi_enable(&tp->napi); + mutex_unlock(&tp->control); + } else { + tp->rx_copybreak = val; + } } break; default: @@ -5274,9 +5280,15 @@ static int rtl8152_set_ringparam(struct net_device *netdev, return -EINVAL; if (tp->rx_pending != ring->rx_pending) { - napi_disable(&tp->napi); - tp->rx_pending = ring->rx_pending; - napi_enable(&tp->napi); + if (netdev->flags & IFF_UP) { + mutex_lock(&tp->control); + napi_disable(&tp->napi); + tp->rx_pending = ring->rx_pending; + napi_enable(&tp->napi); + mutex_unlock(&tp->control); + } else { + tp->rx_pending = ring->rx_pending; + } } return 0;