Re: git: cda31e734925 - main - xhci(4): Ensure the so-called data toggle gets properly reset.

From: Hans Petter Selasky <hselasky_at_freebsd.org>
Date: Tue, 03 May 2022 06:40:09 UTC 
On 5/3/22 00:25, Nathan Whitehorn wrote:
> After this change, I cannot use devices attached to the USB 3 hub in my 
> Dell monitor anymore. The hub appears properly, but any device plugged 
> into it just leaves this in dmesg:
> ugen0.3: <Unknown > at usbus0 (disconnected)
> 
> Note that there is no corresponding connected message or anything else.
> 
> This is with an AMD XHCI controller:
> xhci0@pci0:2:0:0:       class=0x0c0330 rev=0x02 hdr=0x00 vendor=0x1022 
> device=0x43bb subvendor=0x1b21 subdevice=0x1142
>      vendor     = 'Advanced Micro Devices, Inc. [AMD]'
>      device     = '300 Series Chipset USB 3.1 xHCI Controller'
> 


Hi Nathan,

There is an ongoing discussion at (where you may upload USB debug logs 
from the XHCI controller).

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=262882

Can you try to "usbreset -d ugenX.Y" where ugenX.Y corresponds to the 
address of the parent USB HUB for these devices. Do the devices come back?

I'm currently mostly testing on Intel chipsets, and don't see any such 
issues!

I believe the patch is correct, but maybe needs to be adapted to AMD's 
XHCI controllers.

--HPS