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* USB network gadget / DWC3 issue
@ 2021-03-30 12:37 Andy Shevchenko
  2021-03-30 16:17 ` Felipe Balbi
  0 siblings, 1 reply; 27+ messages in thread
From: Andy Shevchenko @ 2021-03-30 12:37 UTC (permalink / raw)
  To: Thinh Nguyen; +Cc: Alan Stern, USB, Ferry Toth, Felipe Balbi

Hi!

I have a platform with DWC3 in Dual Role mode. Currently I'm
experimenting on v5.12-rc5 with a few patches (mostly configuration)
applied [1]. I'm using Debian Unstable on the host machine and
BuildRoot with the above mentioned kernel on the target.

**So, scenario 0:
1. Run iperf3 -s on target
2. Run iperf3 -c ... -t 0 on the host
3.  0.00-10.36  sec   237 MBytes   192 Mbits/sec                  receiver

**Scenario 1:
1. Now, detach USB cable, wait for several seconds, attach it back,
repeat above:
0.00-9.94   sec   209 MBytes   176 Mbits/sec                  receiver

Note the bandwidth drop (177 vs. 192).

(Repeating scenario 1 will give now the same result)

**Scenario 2.
1. Detach USB cable, attach a device, for example USB stick,
2. See it being enumerated and detach it.
3. Attach cable from host
4 .   0.00-19.36  sec   315 MBytes   136 Mbits/sec                  receiver

Note even more bandwidth drop!

(Repeating scenario 1 keeps the same lower bandwidth)

NOTE, sometimes on this scenario after several seconds the target
simply reboots (w/o any logs [from kernel] printed)!

So, any pointers on how to debug and what can be a smoking gun here?

Ferry reported this in [2]. There are different kernel versions and
tools to establish the connection (like connman vs. none in my case).

[1]: https://github.com/andy-shev/linux/
[2]: https://github.com/andy-shev/linux/issues/31


-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 27+ messages in thread

end of thread, other threads:[~2021-04-13 21:21 UTC | newest]

Thread overview: 27+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-30 12:37 USB network gadget / DWC3 issue Andy Shevchenko
2021-03-30 16:17 ` Felipe Balbi
2021-03-30 20:26   ` Ferry Toth
2021-03-30 21:57     ` Ferry Toth
2021-04-02 19:12       ` Ferry Toth
2021-04-02 20:16         ` Thinh Nguyen
2021-04-02 22:40           ` Ferry Toth
2021-04-03  2:02             ` Thinh Nguyen
2021-04-03 11:25               ` Ferry Toth
2021-04-03 21:15                 ` Ferry Toth
2021-04-05 20:59                   ` Ferry Toth
2021-04-07  0:10                     ` Thinh Nguyen
2021-04-07  0:24                       ` Thinh Nguyen
2021-04-07 13:34                         ` Andy Shevchenko
2021-04-07 16:08                           ` Ferry Toth
2021-04-08 20:17                           ` Ferry Toth
2021-04-08 21:12                             ` Thinh Nguyen
2021-04-08 21:37                               ` Thinh Nguyen
2021-04-09 13:26                               ` Ferry Toth
2021-04-10 13:29                                 ` Ferry Toth
2021-04-10 14:08                                   ` Ferry Toth
2021-04-11  0:04                                     ` Thinh Nguyen
2021-04-11 15:26                                       ` Ferry Toth
2021-04-13  2:17                                         ` Thinh Nguyen
2021-04-13  8:45                                           ` Ferry Toth
2021-04-13 21:06                                           ` Ferry Toth
2021-04-13 21:21                                             ` Thinh Nguyen

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