Re: RES: TP-LINK USB no carrier after speed test

From: Hans Petter Selasky <hps_at_selasky.org>
Date: Mon, 26 Sep 2022 21:29:18 UTC 
On 9/26/22 21:28, Alexander Motin wrote:
> Ivan,
> 
> On 26.09.2022 13:11, Ivan Quitschal wrote:
>> bad news im afraid, problem occurred at the first attempt on 
>> speedtest.net.
>> and I'm really trying to help you analizying this code here myself, 
>> but problem is: im far from expert on network protocol business. if it 
>> is a network problem at all. seems to me more like a USB protocol 
>> limit issue or something ..  just FYI , limiting that first constant 
>> to 2048 still limits my  upload to 90mbps , and also still solves the 
>> issue .. there has to be something about it obviously
> 
> On my tests I found that reduction of URE_MAX_TX from 4 to 1 actually 
> help a lot more without so dramatic performance decrease.  Though it is 
> likely only a workaround and does not explain the cause, so I hope Hans 
> more ideas for us to test. ;)
> 

Hi,

I've got a supposedly "broken" if_ure dongle from Alexander, but I'm 
unable to reproduce the if_ure hang on two different pieces of XHCI 
hardware, Intel based and AMD based, which I've got.

This leads me to believe there is a bug in the XHCI driver or hardware 
on your system.

Can you share the pciconfig -lv output for your XHCI controllers?

Also, when running the stress test and you see the traffic stops, what 
happens if you run this command as root on the ugen which the if_ure 
belongs to:

usbconfig -d ugenX.Y dump_string 0

Does the traffic resume?

--HPS