Anyone using BOOTP with latest current (Book-E)?

[Marcel Moolenaar]

On Mar 23, 2010, at 4:03 PM, Pyun YongHyeon wrote:
>> I looked at whether we restart autoneg if the PHY is in autoneg already because
>> I've seen at Juniper how that can contribute to excessive link flaps and even
>> excessive autoneg completion times (>40 seconds) depending on the switch and
>> did this:
>> 
>> Index: dev/mii/ciphy.c
>> ===================================================================
>> --- dev/mii/ciphy.c	(revision 205451)
>> +++ dev/mii/ciphy.c	(working copy)
>> @@ -176,13 +176,11 @@
>> 
>> 		switch (IFM_SUBTYPE(ife->ifm_media)) {
>> 		case IFM_AUTO:
>> -#ifdef foo
>> 			/*
>> 			 * If we're already in auto mode, just return.
>> 			 */
>> 			if (PHY_READ(sc, CIPHY_MII_BMCR) & CIPHY_BMCR_AUTOEN)
>> 				return (0);
>> -#endif
>> 			(void) mii_phy_auto(sc);
>> 			break;
>> 		case IFM_1000_T:
>> 
>> 
>> Apparently the author already considered the same and it does resolve the issue.
>> Anyone see any concerns with my applying this patch?
>> 
> 
> I'm not sure but I guess the #ifdef foo block could be completely
> nuked. The auto-negotiation timeout is set to 17 seconds for
> gigabit link and ciphy(4) will reprogram BMCR if auto-negotiation
> was not resolved after that timeout.

That's besides the point. calling mii_phy_auto() while autoneg is
ongoing aborts the autoneg and restarts it. This causes a link flap
and makes some switches cranky.

What the patch does is to not enable autoneg when autoneg is already
enabled so that we don't interfere with the autoneg handshake.

-- 
Marcel Moolenaar
xcllnt at mac.com