lkml.org 
[lkml]   [2018]   [Jun]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/1] r8152: napi hangup fix after disconnect
Date
When unplugging an r8152 adapter while the interface is UP, the NIC
becomes unusable. usb->disconnect (aka rtl8152_disconnect) deletes
napi. Then, rtl8152_disconnect calls unregister_netdev and that invokes
netdev->ndo_stop (aka rtl8152_close). rtl8152_close tries to
napi_disable, but the napi is already deleted by disconnect above. So
the first while loop in napi_disable never finishes. This results in
complete deadlock of the network layer as there is rtnl_mutex held by
unregister_netdev.

So avoid the call to napi_disable in rtl8152_close when the device is
already gone.

The other calls to usb_kill_urb, cancel_delayed_work_sync,
netif_stop_queue etc. seem to be fine. The urb and netdev is not
destroyed yet.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: linux-usb@vger.kernel.org
Cc: netdev@vger.kernel.org
---
drivers/net/usb/r8152.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index c08c0d633407..1fd165090163 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -3964,7 +3964,8 @@ static int rtl8152_close(struct net_device *netdev)
#ifdef CONFIG_PM_SLEEP
unregister_pm_notifier(&tp->pm_notifier);
#endif
- napi_disable(&tp->napi);
+ if (!test_bit(RTL8152_UNPLUG, &tp->flags))
+ napi_disable(&tp->napi);
clear_bit(WORK_ENABLE, &tp->flags);
usb_kill_urb(tp->intr_urb);
cancel_delayed_work_sync(&tp->schedule);
--
2.17.1
\
 
 \ /
  Last update: 2018-06-25 09:26    [W:0.059 / U:0.328 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site