properly. This causes the autonegotiation to e.g. never establish a
100baseTX full-duplex link. The solution to this problem is to manually
write the capabilities from the BMSR to the ANAR every time a media
change occurs, even when already in autonegotiation mode.
The NetBSD way of doing this is to set their MIIF_FORCEANEG flag in the
NIC driver. This causes mii_phy_setmedia() to call mii_phy_auto() (which
will set the ANAR according to the BMSR) even when the PHY alread is in
autonegotiation mode. However, while doing the same on FreeBSD (which
involves porting the MIIF_FORCEANEG flag and converting nsphy.c to use
mii_phy_setmedia()) fixes autonegotiation, using mii_phy_setmedia()
causes this driver to no longer work properly in the other modes.
Another drawback of that approach is that this will also force writing
the ANAR on other PHYs whose drivers use mii_phy_setmedia() and which
are used with a NIC whose driver sets MIIF_FORCEANEG (e.g. hme(4) is
known to be used together with 3 different PHYs while only the DP83840A
require this workaround).
So instead of moving to MIIF_FORCEANEG, just call mii_phy_auto() in
nsphy_service() unconditionally when hanging off of a hme(4) and serving
a media change
This is part 1/2 of fixing autonegotiation on hme(4) using DP83840A PHYs.
Rename mii_phy_auto_stop() mii_phy_down().
Introduce mii_down(), use it from nge. Do not indirect it to 19 identical
case's in 19 switchstatements like NetBSD did.
. Make internal service routines static.
. Use a consistent ordering of checks in MII_TICK. Do the work in the
mii_phy_tick() subroutine if appropriate.
. Call mii_phy_update() to trigger the callbacks.
The 3C509-TX card apparently had a slightly different version of the
chip, and has problems when this register is set. The problem does
not appear on the 3C509{BC} cards, but since only the fxp driver needs
specific bits set, conditionalize on that.
MII-compliant PHY drivers. Many 10/100 ethernet NICs available today
either use an MII transceiver or have built-in transceivers that can
be programmed using an MII interface. It makes sense then to separate
this support out into common code instead of duplicating it in all
of the NIC drivers. The mii code also handles all of the media
detection, selection and reporting via the ifmedia interface.
This is basically the same code from NetBSD's /sys/dev/mii, except
it's been adapted to FreeBSD's bus architecture. The advantage to this
is that it automatically allows everything to be turned into a
loadable module. There are some common functions for use in drivers
once an miibus has been attached (mii_mediachg(), mii_pollstat(),
mii_tick()) as well as individual PHY drivers. There is also a
generic driver for all PHYs that aren't handled by a specific driver.
It's possible to do this because all 10/100 PHYs implement the same
general register set in addition to their vendor-specific register
sets, so for the most part you can use one driver for pretty much
any PHY. There are a couple of oddball exceptions though, hence
the need to have specific drivers.
There are two layers: the generic "miibus" layer and the PHY driver
layer. The drivers are child devices of "miibus" and the "miibus" is
a child of a given NIC driver. The "miibus" code and the PHY drivers
can actually be compiled and kldoaded as completely separate modules
or compiled together into one module. For the moment I'm using the
latter approach since the code is relatively small.
Currently there are only three PHY drivers here: the generic driver,
the built-in 3Com XL driver and the NS DP83840 driver. I'll be adding
others later as I convert various NIC drivers to use this code.
I realize that I'm cvs adding this stuff instead of importing it
onto a separate vendor branch, but in my opinion the import approach
doesn't really offer any significant advantage: I'm going to be
maintaining this stuff and writing my own PHY drivers one way or
the other.
