Can someone tell me how to use the mii command? I have the following from a dump:
uBOOT=>> mii dump MII not complete 0. (ffff) -- PHY control register -- (8000:8000) 0.15 = 1 reset (4000:4000) 0.14 = 1 loopback (2040:2040) 0. 6,13 = b11 speed selection = ??? Mbps (1000:1000) 0.12 = 1 A/N enable (0800:0800) 0.11 = 1 power-down (0400:0400) 0.10 = 1 isolate (0200:0200) 0. 9 = 1 restart A/N (0100:0100) 0. 8 = 1 duplex = full (0080:0080) 0. 7 = 1 collision test enable (003f:003f) 0. 5- 0 = 63 (reserved) On Wed, Jan 7, 2009 at 12:58 PM, Jerry Van Baren <gerald.vanba...@ge.com> wrote: > Ulf Samuelsson wrote: >> >> ons 2009-01-07 klockan 07:52 -0500 skrev Jerry Van Baren: >>> >>> Wolfgang Denk wrote: >>>> >>>> Dear Ulf Samuelsson, >>>> >>>> In message <1231282371.32308.276.ca...@elrond.atmel.com> you wrote: >>>>> >>>>> It was tracked down to the autoconfiguration of the Ethernet PHY, so >>>>> one of the PHYs ended up in 100 Mbps Half Duplex (think that was the >>>>> switch) >>>>> while the other PHY ended up in 100 MBps Full Duplex. >>>> >>>> That would most probably be a bug in the U-Boot ethernet driver, then. >>>> >>>> Best regards, >>>> >>>> Wolfgang Denk >>> >>> If auto-negotiation fails, the default is half duplex (10 or 100 - the >>> speed can be discovered independent of the autonegotiation by the encoding). >>> >>> Ulf's recollection that the switch was half duplex would indicate that >>> the cheap switch did not autonegotiate properly, but u-boot did. This could >>> be a u-boot bug (not setting up the negotiation properly), but more likely >>> would be a switch problem (not handling the u-boot auto-neg options >>> properly). >>> >> >> Don't remember all details, since it was 4 years ago. >> I talked to D-Link support and they claimed that the standard >> was to fall back to one of the options, if autonegotiation failed. > > Autonegotiation enabled but fails => half duplex. It's in the spec. > >> The customer might have had a PHY without autonegotation which >> was hardwired to 100 Mbps full duplex. > > Manually configured (autoneg disabled) is no problem, *AS LONG AS* both > sides are manually configured to the same configuration. The problem is > when one side is configured to autonegotiate and the other side is set to > full duplex. The autonegotiation side is unable to negotiate with the > manually configured side, so it falls back to half duplex at whatever rate > is being used (10/100, determined from the encoding on the wire). > > It sorta works until there is more than a few packets on the wire, at which > time the half duplex end sees the full duplex packets as collisions and the > error rate (and runt packets) skyrockets because the half duplex side keeps > aborting packets. > > It sounds like, in your case, the computer end was manually configured to be > (100bT) full duplex but the (cheap unmanaged) switch was still running > auto-negotiation. Recipe for disaster. > >> With little communication, the packages were sent where this caused some >> problems. > > Oh yeah, in spades, but only when the wire gets busier. > > gvb > > -- -- --------------------------------------------- Loren A. Linden Levy Department of Physics 390 UCB University of Colorado Boulder, CO 80309-0390 Tel: 303-735-6146 (CU) / +049 040 8998 4789 (DESY) Fax: 303-492-3352 (CU) / +049 040 8998 4034 (DESY) Cell: 303-332-2768 (U.S.) / +049 (0)151 5496 1831 (Germany) Email: loren.lindenl...@colorado.edu url: http://up.colorado.edu/~lindenle _____________________________________________ --------------------------------------------- This email has been cryptographically signed. Search for "lindenle" at pgp.mit.edu to obtain my public key which can be used to verify the authenticity of this message. _____________________________________________ --------------------------------------------- _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot