From da970765b24cad557bde1b0372166e46c1276230 Mon Sep 17 00:00:00 2001 From: Xiao Liang Date: Fri, 27 Jul 2018 17:56:08 +0800 Subject: [PATCH] xen-netfront: wait xenbus state change when load module manually [ Upstream commit 822fb18a82abaf4ee7058793d95d340f5dab7bfc ] When loading module manually, after call xenbus_switch_state to initializes the state of the netfront device, the driver state did not change so fast that may lead no dev created in latest kernel. This patch adds wait to make sure xenbus knows the driver is not in closed/unknown state. Current state: [vm]# ethtool eth0 Settings for eth0: Link detected: yes [vm]# modprobe -r xen_netfront [vm]# modprobe xen_netfront [vm]# ethtool eth0 Settings for eth0: Cannot get device settings: No such device Cannot get wake-on-lan settings: No such device Cannot get message level: No such device Cannot get link status: No such device No data available With the patch installed. [vm]# ethtool eth0 Settings for eth0: Link detected: yes [vm]# modprobe -r xen_netfront [vm]# modprobe xen_netfront [vm]# ethtool eth0 Settings for eth0: Link detected: yes Signed-off-by: Xiao Liang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netfront.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 04e0765be5e7..dfc076f9ee4b 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -87,6 +87,7 @@ struct netfront_cb { /* IRQ name is queue name with "-tx" or "-rx" appended */ #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3) +static DECLARE_WAIT_QUEUE_HEAD(module_load_q); static DECLARE_WAIT_QUEUE_HEAD(module_unload_q); struct netfront_stats { @@ -1330,6 +1331,11 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev) netif_carrier_off(netdev); xenbus_switch_state(dev, XenbusStateInitialising); + wait_event(module_load_q, + xenbus_read_driver_state(dev->otherend) != + XenbusStateClosed && + xenbus_read_driver_state(dev->otherend) != + XenbusStateUnknown); return netdev; exit: -- 2.20.1