Re: kern/55067: bge(4) does not work on MIPS systems (it panics)

[Jason Thorpe <thorpej%me.com@localhost>]

> On Mar 12, 2020, at 4:25 PM, Jason Thorpe <thorpej%me.com@localhost> wrote:
> 
> Yah, it stops crashing once I fix that.  But it still doesn't work.  Although, I think THAT problem is an issue with my test set-up.  I'm using it in a 32-bit slot, but I suspect the firmware on the board thinks it got plugged into a 64-bit slot; I noticed that my "gsip" board also thinks it's connected to a 64-bit slot on this system.
> 
> I believe that ACK64# and REQ64# are supposed to be left floating on a 32-bit slot (I need to re-read the spec to be sure).  I'm guessing that they're being pulled in some direction they're not supposed to be on the Qube2 mainboard, causing the card to mis-detect.  That will cause half of the data path to march off a cliff.  Luckily, to make these cards physically fit the machine, I have to use a couple of risers in a sort of Rube Goldberg arrangement, so if I'm right about what's supposed to happen with ACK64# and REQ64#, I'll simply cut those traces on the risers.

Well, I recalled incorrectly about 64-bit slot detection.

ACK64# and REQ64# are supposed to be pulled high by the system board on 32-bit slots according to PCI 2.1... but I need to dig up an older version of the spec to see if those pins were floating / NC prior to PCI 2.x.

However, it may simply be the case that these boards don't work in 32-bit slots ... I tried a D-Link DGE-550T (64-bit card, "stge") and it worked perfectly.

-- thorpej