Subject: Re: Gigabit Ethernet support on gmac?
To: Monroe Williams <>
From: Jason R Thorpe <>
List: port-macppc
Date: 10/18/2001 13:23:28
On Thu, Oct 18, 2001 at 11:43:14AM -0700, Monroe Williams wrote:

 > Congratulations.  It looks like you got the MAC address code right the first
 > time.  ;)  Not only does it build, the interface has the same MAC address
 > with the gem driver that it had with the gm driver.


 > With a kernel that generates this dmesg output:
 > gem0 at pci2 dev 15 function 0: Apple Computer GMAC Ethernet (rev. 0x01)
 > gem0: interrupting at irq 41
 > gem0: Ethernet address 00:30:65:d6:f3:de
 > brgphy0 at gem0 phy 0: BCM5401 1000BASE-T media interface, rev. 3
 > brgphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT,
 > 1000baseT-FDX, auto
 > If I boot the machine while connected to a 100baseTX switch, it doesn't
 > autodetect.  (ifconfig shows "media: Ethernet autoselect (none)".)  I can
 > get connectivity by doing `ifconfig gem0 media 100baseTX-FDX`.  If I then
 > set the media back to autoselect, it seems to work fine thereafter.  I can
 > hot-plug the cable as needed, the ifconfig output reflects the state of the
 > world, and the interface works as expected.

Ok, I suppose this means that the behavior you're observing is different
from that of the "gm" driver.  The MII/PHY setup in the "gem" driver is
a bit different -- I'll poke around and see if I can find anything

 > I can't get gigabit to work at all.  If I hot-plug the cable into the
 > gigabit switch, the link lights show a 1G link and ifconfig shows
 > media: Ethernet autoselect (1000baseTX full-duplex)
 > but no packets flow.  I've tried various manual media configurations with no
 > joy.  Booting the machine while connected to the gigabit switch works no
 > better.

Ok ... this means there's probably some MAC setup missing for Gig-E speeds.
I'll take a look into this, too.

 > The results are mostly the same, but when it's plugged into the Gigabit
 > switch in autoconfig mode, ifconfig shows:
 > media: Ethernet autoselect (100baseTX full-duplex)
 > which doesn't match what the lights on the switch show (1G link).

Right, because ukphy doesn't know how to figure out what the Gig-E
media is ... I should be able to fix this, too.

        -- Jason R. Thorpe <>