This bug may or may not be related to bug #60521 usbnet changes in 3.10 stop use of sierra_net devices Since both resolutions are different, I decided to create a new bug. With kernels 3.10.4 and 3.10.0, my Delock USB Ethernet adapter (using a MosChip device) hardly survives the DHCP phase, then quickly becomes unresponsive. Sometimes even during DHCP. Things went back to normal after reverting commit 4be74c130d1c5c03bccef0ab8d7a6bb71c7de53a usbnet: mcs7830: apply usbnet_link_change I haven't digged any further so far. Till
Further debugging (thanks to Ming Lei) revealed that the chipset produces permanent link on/off oscillation and apparently the frequent calls of usbnet_defer_kevent(dev, EVENT_LINK_CHANGE); (in usbnet_link_change()) make it hang after a short while. Said call was indirectly introduced by commit 4be74c13(usbnet: mcs7830: apply usbnet_link_change), so this is why its reversion `solved' my problem. Hence the actual problem is the permanent oscillation, as already mentioned by commit dabdaf0c(mcs7830: Fix link state detection). I tried using 200 instead of 20, but it didn't help as the (my) device apparently never stops oscillating.