Realtek RTL8191SU really slow with „N” mode enabled

Realtek RTL8191SU really slow with „N” mode enabled

[Szőts Ákos]

Dear list members,

I have a "0bda:8172 Realtek RTL8191SU 802.11n WLAN Adapter” working
- previously with kernel v4.0 staging driver r8712u,
- and now with wireless kernel v4.1 driver rtl8192su (from 
https://github.com/chunkeey/rtl8192su).

My problem is when, by default, the 802.11n mode is enabled, the USB dongle's 
connection speed is only around 1 Mb/s (with both drivers). When I turn it off 
with "options rtl8192su ht_enable=0" in its config file, I get my full internet 
speed, about 30 Mb/s.

I'm asking whether it's a problem in the firmware or somewhere in the driver 
code? If it's the latter case and you're interested in, I would like to help 
debugging the problem and help you to fix this issue.

Thank you very much.

All the best,

Ákos

Re: Realtek RTL8191SU really slow with „N” mode enabled

[Christian Lamparter]

Hello,

On Saturday, June 27, 2015 11:16:21 AM Szőts Ákos wrote:
> I have a "0bda:8172 Realtek RTL8191SU 802.11n WLAN Adapter” working
> - previously with kernel v4.0 staging driver r8712u,
> - and now with wireless kernel v4.1 driver rtl8192su (from 
> https://github.com/chunkeey/rtl8192su).
> 
> My problem is when, by default, the 802.11n mode is enabled, the USB dongle's 
> connection speed is only around 1 Mb/s (with both drivers). When I turn it off 
> with "options rtl8192su ht_enable=0" in its config file, I get my full internet 
> speed, about 30 Mb/s.

Wait! There isn't any ht_enable option for the rtl8192su(.ko) driver...?!

> I'm asking whether it's a problem in the firmware or somewhere in the driver 
> code? If it's the latter case and you're interested in, I would like to help 
> debugging the problem and help you to fix this issue.
Can't help you with debugging the problem as long as I can't reproduce the
issue. No idea if this is a hardware, firmware, driver, setup or some
kind of interaction issue. In my opinion: you simply disable HT, then you
just did take a feature away rather than dealing with anything. But, if
that's what you want: fine.

Note: I think the simplest solution would be to have a working reference.
If you are looking for a wifi usb-stick, ath9k_htc solutions are usually
the way to go.

Regards,
  Christian