Re: Call for testers: Atheros AR8121(L1E)/AR8113/AR8114(L2E) ethernet

On Thu, Dec 11, 2008 at 10:23:50PM -0500, Josh Carroll wrote:
 > > Would you show me the output of "sysctl dev.ale.0.stats"?
 > 
 > Here is the output shortly after a reboot, before I try to stream anything:
 > 
 > dev.ale.0.stats.rx.good_frames: 1843
 > dev.ale.0.stats.rx.good_bcast_frames: 9
 > dev.ale.0.stats.rx.good_mcast_frames: 0
 > dev.ale.0.stats.rx.pause_frames: 0
 > dev.ale.0.stats.rx.control_frames: 0
 > dev.ale.0.stats.rx.crc_errs: 0

[...]

 > And after trying to stream (I let it struggle along for about 30-40 seconds):
 > 
 > dev.ale.0.stats.rx.good_frames: 4350
 > dev.ale.0.stats.rx.good_bcast_frames: 35
 > dev.ale.0.stats.rx.good_mcast_frames: 0
 > dev.ale.0.stats.rx.pause_frames: 3636
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 > dev.ale.0.stats.rx.control_frames: 0
 > dev.ale.0.stats.rx.crc_errs: 0

[...]

I guess it's caused by flow-control frames.
The flow-control feature is disabled in most drivers as mii(4)
layer still lacks the feture. ale(4) has flow-control support code
but it is in disabled state. When mii(4) is ready to handle
flow-controls ale(4) may work better.
em(4) does not rely on mii(4) layer so it implemented flow-controls
in driver. You can check flow-control satus of em(4) with
"sysctl dev.em.0.stats=1"(See XON/XOFF).

-- 
Regards,
Pyun YongHyeon