Re: disabling mediaopts for if_wm(4)

[Paul Goyette <paul%whooppee.com@localhost>]

On Tue, 9 May 2017, David Young wrote:

> On Wed, May 10, 2017 at 09:35:44AM +0800, Paul Goyette wrote:
> > Well, I got a little bit of a problem...
> >
> > My new fiber-to-the-home router only has one RJ45 port available, so
> > I had to get a switch to connect all of the hard-wired network
> > devices. It all seems to work, except for one problem...
> >
> > In the uplink direction, I can only push about 3.5Mb/sec, compared
> > to the expected 50Mb/sec in the download direction.  And, if I
> > directly connect to the router's RJ45 port I can also get 50Mb/sec
> > upload speed.
> >
> > So, the upload problem happens only with the switch.
>
> ISTR that wm(4) has one or more bugs concerning flow control.  It's
> possible that when flow control is negotiated, the MAC is not set up to
> respect flow control signals, so it keeps sends frames to the peer after
> it is asked to pause.  With all buffers full, the peer drops the frames
> on the floor.  This would be an important bug to fix.
>
> Does your switch tell how many frames are dropped?

The switch doesn't tell anything!  :)  It's a real el-cheapo - US$15, 
purchased locally here in the Philppines.  (And I've seen adverts for 
even less, US$12!)

FWIW, this is a D-Link DEC-1008A 8-port 10/100 with auto-MDI/MDIX.



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