On 13/11/2016 20:55, Florian Fainelli wrote: > Le 13/11/2016 à 11:51, Mason a écrit : >> On 13/11/2016 04:09, Andrew Lunn wrote: >> >>> Mason wrote: >>> >>>> When connected to a Gigabit switch >>>> 3.4 negotiates a LAN DHCP setup instantly >>>> 4.7 requires over 5 seconds to do so >>> >>> When you run tcpdump on the DHCP server, are you noticing the first >>> request is missing? >>> >>> What can happen is the dhclient gets started immediately and sends out >>> its first request before auto-negotiation has finished. So this first packet >>> gets lost. The retransmit after a few seconds is then successful. >> >> I will run tcpdump on the server as I run udhcpc on the client >> for Linux 3.4 vs 4.7 >> >> Do you know what would make auto-negotiation fail at 100 Mbps >> on 4.7? (whereas it succeeds on 3.4) >> >> (Thinking out loud) If the problem were in auto-negotiation, >> then if should work if I hard-code speed and duplex using >> ethtool, right? (IIRC, hard-coding doesn't help.) > > I would start with checking basic things: > > - does your Ethernet driver get a link UP being reported correctly > (netif_carrier_ok returns 1)?
I don't see any calls to netif_carrier_ok() in the network driver ( drivers/net/ethernet/aurora/nb8800.c ) Maybe it is using some generic infrastructure? > - if you let the bootloader configure the PHY and utilize the Generic > PHY driver instead of the Atheros PHY driver, does the problem appear as > well? How exactly does one use the generic PHY driver? Do you mean the following? Documentation/devicetree/bindings/net/fixed-link.txt Regards.
