Expected issue? Old PowerMac G5 [...] vs. USB [...] [RealTek EtherNet] devices (...)

[Mark Millard]

On 2021-Feb-1, at 14:28, John-Mark Gurney <jmg at funkthat.com> wrote:

> Mark Millard wrote this message on Mon, Feb 01, 2021 at 13:34 -0800:
>> On 2021-Feb-1, at 11:47, John-Mark Gurney <jmg at funkthat.com> wrote:
>> 
>>> Mark Millard wrote this message on Sun, Jan 31, 2021 at 13:45 -0800:
>>>> . . .
>>>> So far it seems to be working just fine. I'm using it
>>>> without hw.usb.xhci.use_polling=1 .
>>> 
>>> Is the axge a USB3 or USB3 device?  The driver attached to both...
>> 
>> The axge, like all my USB Ethernet devices, is USB3 capable but
>> is supposed to support use in USB2 contexts. The PowerMac, of
>> course, is old and only has USB2.
> 
> Then why bother w/ xhci?  Since that should apply only to USB3
> controllers... If your mac isn't USB3 compatible, shouldn't be
> detected/probed/used, and you should only have ehci...
> 
> This is why I was puzzled, tweaking xhci implies that the system is
> USB3 capable...
> 
> (if xhci changes USB2 behavior, then it needs to be renamed)...

Given the variability in behavior I'm seeing, I likely
mistook an accidental correspondence back during the
summer as a "this makes a difference for whatever reason".
I had left material around to remind me that I'd used
hw.usb.xhci.use_polling=1 back then, but not any detail.

Technically I do not have the knowledge of the software
structure to rule out its getting to ehci support
indirectly.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)