On Wed, 17 Apr 2019 03:49:46 +0000 <RaghuramChary.Jallipalli@xxxxxxxxxxxxx> wrote: > > Hi Jisheng, Hi, > > > > I want to understand if there is any functionality impact with this warning? > > Because I'm afraid if the current changes are removed we might hit some > > other issues (or older ones). We have to go through rigorous testing before > > going ahead. > > > > Warning indicates there's something wrong in the code. > > Agree that the code is incorrect. Just wanted to understand if you had any functionality impact too. > > > > > IMHO phy_mac_interrupt() and PHY_IGNORE_INTERRUPT is the correct > > solution. If the phy_mac_interrupt() poll is fixed, I think maybe old issue > > which commit cc89c323a30e want to fix won't exist. > > > > I tried to reproduce the problem in PC environment but did not see the warnings. > However, I tried your patch and did plug/unplug tests(rmmod/insmod continuously) and observed call traces from kernel. I don't see these traces without your patch. > Attached log. I believe this is another bug in lan78xx driver: after phy_disconnect() if there's intr urb coming, we will call phy_mac_interrupt, so trigger phy_state_machine(), but now the phydev->attached_dev is NULL, so NULL pointer deference. Can you please try below patch: --->8 diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c index 246a0d1bbc6c..27d6fbdd58c1 100644 --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -3467,6 +3467,8 @@ static void lan78xx_disconnect(struct usb_interface *intf) net = dev->net; phydev = net->phydev; + usb_kill_urb(dev->urb_intr); + phy_unregister_fixup_for_uid(PHY_KSZ9031RNX, 0xfffffff0); phy_unregister_fixup_for_uid(PHY_LAN8835, 0xfffffff0); @@ -3483,7 +3485,6 @@ static void lan78xx_disconnect(struct usb_interface *intf) lan78xx_unbind(dev, intf); - usb_kill_urb(dev->urb_intr); usb_free_urb(dev->urb_intr); free_netdev(net);
