From bd869245a3dcca1c8a77dfade7d3dc69a68365df Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Sat, 20 Jun 2020 22:35:42 +0200 Subject: [PATCH] net: core: try to runtime-resume detached device in __dev_open A netdevice may be marked as detached because the parent is runtime-suspended and not accessible whilst interface or link is down. An example are PCI network devices that go into PCI D3hot, see e.g. __igc_shutdown() or rtl8169_net_suspend(). If netdevice is down and marked as detached we can only open it if we runtime-resume it before __dev_open() calls netif_device_present(). Therefore, if netdevice is detached, try to runtime-resume the parent and only return with an error if it's still detached. Signed-off-by: Heiner Kallweit Signed-off-by: David S. Miller --- net/core/dev.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index cea7fc1716ca..c5ec4d50acd1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -143,6 +143,7 @@ #include #include #include +#include #include "net-sysfs.h" @@ -1492,8 +1493,13 @@ static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack) ASSERT_RTNL(); - if (!netif_device_present(dev)) - return -ENODEV; + if (!netif_device_present(dev)) { + /* may be detached because parent is runtime-suspended */ + if (dev->dev.parent) + pm_runtime_resume(dev->dev.parent); + if (!netif_device_present(dev)) + return -ENODEV; + } /* Block netpoll from trying to do any rx path servicing. * If we don't do this there is a chance ndo_poll_controller